Resident walks through debris next to a building that was hit by shelling in Kyiv

Amid constant battering of Kyiv, Ukraine and Russia both hopeful about talks

KYIV, Ukraine (AP) — Russia’s military forces battered Ukraine’s capital region and other major cities in a bid to crush the resistance that has frustrated any hopes the Kremlin had for a lightning victory, while the two countries projected optimism for another round of scheduled talks Wednesday.

With Russia’s ground advance on Kyiv stalled despite the sustained bombardment, statements from the two sides suggested room for progress in their negotiations. Russian Foreign Minister Sergey Lavrov said a neutral military status for Ukraine was being “seriously discussed,” while Ukrainian President Volodymyr Zelensky described Russia’s demands for ending the war as becoming “more realistic.”

WATCH: Russia escalates bombardment of Kyiv as civilian casualties mount

Zelensky said Russian forces had been unable to move deeper into Ukrainian territory but had continued their heavy shelling of cities including Mariupol, a southern seaport that has been under attack for almost all of the nearly three-week war.

Kyiv residents huddled in homes and shelters amid a citywide curfew that runs until Thursday morning, as Russia rained shells on areas in and around the city. A 12-story apartment building in central Kyiv erupted in flames after being hit by shrapnel.

“Efforts are still needed, patience is needed,” Zelensky said in his nightly video address to the nation. “Any war ends with an agreement.”

British and U.S. intelligence assessments supported the Ukrainian leader’s view of the fighting, saying Russian ground forces remained about 15 kilometers (9 miles) from the center of Kyiv.

Hopes for diplomatic progress rose after Zelensky said Tuesday that Ukraine realized it could not join NATO, his most explicit acknowledgment that the goal, enshrined in Ukraine’s Constitution, was unlikely to be met. Russian President Vladimir Putin has long depicted Ukraine’s NATO aspirations as a threat to Russia, something the Western military alliance denies.

Lavrov welcomed Zelensky’s comment and said “the businesslike spirit” starting to surface in the talks “gives hope that we can agree on this issue.”

“A neutral status is being seriously discussed in connection with security guarantees,” Lavrov said Wednesday on Russian channel RBK TV. “There are concrete formulations that in my view are close to being agreed.”

Russia’s chief negotiator, Vladimir Medinsky, said the sides were discussing a possible compromise idea for a future Ukraine with a smaller, non-aligned military.

Prospects of a diplomatic breakthrough were highly uncertain, however, with a gulf between Ukraine’s demand that the invading forces withdraw completely and Russia’s suspected war aim of replacing Kyiv’s Westward-looking government with pro-Moscow leadership.

Ukrainian presidential adviser Mykhailo Podolyak denied Russian claims Ukraine was open to adopting a model of neutrality comparable to Sweden or Austria’s. Podolyak said on Telegram that Ukraine needed powerful allies and “clearly defined security guarantees” to keep it safe.

Zelensky was making a direct appeal for more American help Wednesday in a rare speech by a foreign leader to the U.S. Congress, with President Joe Biden set to announce $800 million in new military assistance to Ukraine, according to a White House official.

READ MORE: European human rights council expels Russia over Ukrainian war

There was no immediate prospect of an end to the fighting that has upended Europe’s post-Cold War security order, driven millions from their homes in Ukraine and turned large parts of the country into war zones.

The U.N. refugee agency says the number of people fleeing Ukraine amid Europe’s heaviest fighting since World War II has passed 3 million. The U.N.’s human rights body reported Wednesday that 726 civilians have been killed and 1,174 injured but acknowledged those numbers were likely an undercount.

The head of the International Committee of the Red Cross, Peter Maurer, arrived in Ukraine on Wednesday to try to obtain greater access for aid groups and increased protection of civilians.

Amid the vast humanitarian crisis caused by the war, the Red Cross has helped evacuate civilians from besieged areas and has delivered 200 tons of aid, including blankets, water and over 5,200 body bags to help “ensure the dead are treated in a dignified manner,”

Nowhere has suffered more than Mariupol, a strategic port city of 430,000 on the Sea of Azov that has been surrounded by Russian troops for two weeks. Local officials say missile strikes and shelling have killed more than 2,300 people and left residents struggling for food, water, heat and medicine.

A mass grave trench contains the bodies of children, and more corpses lie in streets and in a hospital basement awaiting someone to pick them up. With food running out and humanitarian aid unable to get in amid the constant bombardment, people burn scraps of furniture in makeshift grills to warm their hands and cook the little food still available.

In a sign of relief, 20,000 people managed to escape the city on Tuesday in 4,000 vehicles, according to Zelensky’s office.

READ MORE: Small but growing number of women head back into Ukraine

But Ukrainian Deputy Prime Minister Iryna Vereshchuk expressed dismay Wednesday at reports that Russian forces had taken hundreds of people hostage at a Mariupol hospital and were using it as a firing position.

Regional leader Pavlo Kyrylenko said Russian troops forced about 400 people from nearby homes into the Regional Intensive Care Hospital and were using them and roughly 100 patients and staff as human shields by not allowing them to leave.

Doctors from other Mariupol hospitals made a video to tell the world about the horrors they’ve been seeing. “We don’t want to be heroes and martyrs posthumously,” one woman said. She said it was insufficient to refer to the patients being treated as wounded: “It’s torn off arms and legs, gouged out eyes, bodies torn into fragments, insides falling out.”

The artillery shrapnel that hit the 12-story apartment building in central Kyiv on Wednesday obliterated the top floor and ignited a fire that sent plumes of smoke over the area. Residents carried possessions and pets from the building as firefighters doused the flames amid a sea of rubble. The Kyiv emergencies agency said there were two victims, without saying if they were injured or killed.

Kyiv regional leader Oleksiy Kuleba said Russian forces had intensified fighting in the Kyiv suburbs and a highway leading west.

Across the capital region, “kindergartens, museums, churches, residential blocks and engineering infrastructure are suffering from the endless firing,” Kuleba said, and 12 towns around Kyiv were reported to be without water and six without heat.

He said Russian troops were trying to cut off transportation links to the capital and to destroy logistical capabilities while planning a wide-ranging attack to seize the capital.

Russian forces succeeded in occupying the city of Ivankiv, 80 kilometers (50 miles) north of Kyiv, and control the surrounding region on the border with Belarus, Kuleba said.

In addition to airstrikes and shelling by ground forces, Russian naval ships fired overnight on a town south of Mariupol on the Azov Sea and another near Odesa on the Black Sea, according to local officials.

Ukraine also appeared to have successes, with satellite photos from Planet Labs PBC analyzed by The Associated Press showing helicopters and vehicles ablaze at the Russian-held Kherson International Airport and Air Base after a suspected Ukrainian strike on Tuesday.

Zelensky’s office said Ukrainian forces thwarted Russian efforts to enter Kharkiv, Ukraine’s second-largest city, which was pounded by almost non-stop strikes over the last 24 hours. A powerful explosion thundered across the city overnight.

READ MORE: ‘All day crying from the pain’: number of Ukrainian refugees fleeing war hits 2.8 million

Hospital workers in the city found themselves on two frontlines, battling COVID-19 in intensive care units as war raged outside. Air raid sirens go off multiple times daily, forcing fragile patients into the the Kharkiv Regional Clinical Infectious Diseases Hospital’s makeshift bomb shelter, the hospital’s director, Dr. Pavel Nartov, said.

“Bombing takes place from morning into night. Thank god a bomb has not yet hit our hospital. But it could hit at any time,” Nartov told The Associated Press.

Russian Defense Ministry spokesman Igor Konashenkov claimed Russian forces destroyed 111 Ukrainian aircraft, 160 drones and more than 1,000 tanks or other military vehicles since the start of what Russia calls its “special military operation” in Ukraine.

The Russian military’s daily public statements on the war focus almost exclusively on fighting in the separatist-held Donetsk and Luhansk regions, and on Ukrainian military targets, without acknowledging attacks on civilians.

As the West tried to bolster Ukraine’s defenses while ratcheting up sanctions on Russia, defense ministers from NATO member nations met in Brussels on Wednesday ahead of an emergency summit of the military alliance next week.

Meanwhile the prime ministers of Poland, the Czech Republic and Slovenia returned to Poland on Wednesday after a risky visit to Kyiv meant to show support for Ukraine. They went ahead with the hours-long train trip despite worries within the European Union about the security risks.

“Ukraine of these days and weeks needs above all arms supply,“ Czech Prime Minister Petr Fiala said at a Prague airport Wednesday after arriving home from the trip.

He said massive supplies of military equipment have to be delivered quickly by as many countries as possible for Ukraine to have a chance of holding off the invading Russian troops.

“We have to realize that (the Ukrainians) do also fight for our independence, for our freedom, and we have to support them,” Fiala said. “That’s the reason why we traveled there, to show them they’re not alone.“

Associated Press journalists around the world contributed to this report.