WATCH: Senate hearing on U.S. and global response to Russia’s attack on Ukraine

Hours after President Joe Biden announced the U.S. is banning imports of Russian oil, one of the administration’s top diplomats told a Senate panel, “there is more on the way from the G7, our EU partners and countries around the world, if President Putin does not end this vicious war.”

Watch the hearing in the player above.

Undersecretary of State for Political Affairs Victoria Nuland told members of the Senate Foreign Relations Committee that capital is flowing out of Russia, accompanied by a precipitous drop in the value of Russia’s currency, the ruble.

Nuland said Russia is seeing rising inflation, higher borrowing costs and disappearing access to global financial markets.

“We have levied export controls on key industries and the Russian military in close coordination with almost 40 countries around the world, representing over half the world’s economy, and those sanctions have had an immediate impact,” she said.

Nuland also pointed to the administration’s military response to Russia’s invasion.

“We’ve more than doubled our U.S. forces in Poland and sent thousands of troops to the Baltics, to Romania and elsewhere along the flank, along with advanced combat aviation,” she said.

Ukraine has pleaded for more warplanes, and Tuesday Poland said it would give all of its MiG-29 fighter jets to the U.S., apparently agreeing to an arrangement that would allow them to be used by Ukraine’s military.

The decision came as Washington was looking at a proposal under which Poland would supply Ukraine with Soviet-era fighters and in turn receive American F-16s to make up for their loss. Ukrainian pilots are trained to fly Soviet-era fighter jets.

“President Putin has not only attacked Ukraine, he has trashed the U.N. principle of self-determination of states and questioned Ukraine’s very right to exist,” Nuland told the panel.

“As President Biden said, we are now in a battle between democracy and autocracy. And free people, free nations and a free Ukraine must prevail,” she said.