WATCH: Secretary of State Blinken says U.S. has made no concessions to Russia on Ukraine

WASHINGTON (AP) — The U.S. has made no concessions to the main Russian demands over Ukraine and NATO in a long-awaited written response delivered to Russia on Wednesday in Moscow, Secretary of State Antony Blinken said.

Watch Blinken’s remarks in the player above.

Blinken said the U.S. response, delivered to the Russian Foreign Ministry by U.S. Ambassador to Russia John Sullivan, gave up no ground on “core principles” such as NATO’s open-door membership policy and the alliance’s military presence in Eastern Europe.

Blinken said the document made clear that the U.S. is standing by its oft-stated positions. “There is no change, there will be no change,” he said. But, he said the written response to Russia also contains “serious” offers for a diplomatic path to de-escalate soaring tensions over Ukraine by addressing Russian concerns on other matters.

Russia has warned it would quickly take “retaliatory measures” if the U.S. and its allies rejected its demands.

Blinken said he expects to speak again with Russian Foreign Minister Sergey Lavrov in the coming days to get the Russian reaction. But, he said that whether Russia accepts them is entirely the decision of President Vladimir Putin. “That is up to President Putin,” he said. “We’ll see how they respond.”

The U.S. proposals, echoed in a separate document sent to the Russians by NATO, include the potential for negotiations over offensive missile placements and military exercises in Eastern Europe as well as broad arms control agreements as long as Russia withdraws its estimated 100,000 troops from the Ukrainian border.

Moscow has demanded guarantees that NATO will never admit Ukraine and other ex-Soviet nations as members and that the alliance will roll back troop deployments in former Soviet bloc nations. Some of these, like the membership pledge, are nonstarters for the U.S. and its allies, creating a seemingly intractable stalemate that many fear can only end in a war.

The Kremlin has repeatedly denied it has plans to attack Ukraine, but the U.S. and NATO are worried about Russia massing its troops near Ukraine and conducting a series of sweeping military maneuvers.

As part of the drills, motorized infantry and artillery units in southwestern Russia practiced firing live ammunition, warplanes in Kaliningrad on the Baltic Sea performed bombing runs, dozens of warships sailed for training exercises in the Black Sea and the Arctic, and Russian fighter jets and paratroopers arrived in Belarus for joint war games.

Speaking to Russian lawmakers, Lavrov said he and other top officials will advise Putin on the next steps after receiving the U.S. reply.

“If the West continues its aggressive course, Moscow will take the necessary retaliatory measures,” Lavrov said.

But he indicated Russia wouldn’t wait forever. “We won’t allow our proposals to be drowned in endless discussions,” he said.

Yuras Karmanau in Kyiv, Ukraine, and Kirsten Grieshaber in Berlin contributed.