Secretary of State Antony Blinken said on Sunday that NATO member nations are allowed to send fighter jets to Ukraine as the United States and its allies continue to provide assistance to Ukraine in the midst of the ongoing Russian invasion.

Blinken said on CBS’ “Face the Nation,” on Sunday, that NATO allies sending fight jets to Ukraine “gets a green-light.”

He said, “In fact, we’re talking with our Polish friends right now abut what we might be able to do to backfill their needs if in fact they choose to provide fighter jets to the Ukrainians. What can we do? How can we help to make sure that they get something to backfill the planes that they are handing over to the Ukrainians?”

A White House spokesperson told CBS News that the Biden administration is evaluating its ability to provide fighter jets to Poland should the Polish government decide to transfer planes to Ukraine, CBS News reported.

Oksana Markarova, Ukraine’s ambassador to the U.S. said that she hopes Ukraine will receive fighter jets from Poland “as soon as possible.”

She said, “We are working with our American, especially, friends and allies, on the steady supply of ammunition and anti-air, anti-tank, and planes to be able to effectively defend our county.”

Allied Western nations have provided military and humanitarian aide to Ukraine in response to the Russian invasion and have also issued sweeping sanctions that effectively cripple and isolate the Russian financial system.

Shortly after Russia launched its invasion, leaders from the European Commission, France, Germany, Italy, Canada, the United Kingdom, and the U.S. issued a statement expressing their intentions to remove Russian banks from the SWIFT telecommunication network.

The statement said, “We stand with the Ukrainian government and the Ukrainian people in their heroic efforts to resist Russia’s invasion. Russia’s war represents an assault on fundamental international rules and norms that have prevailed since the Second World WAR, which we are committed to defending. We will hold Russia to account and collectively ensure that this war is a strategic failure for Putin.”

Since the West locked arms in support of Ukraine, the Russian economy has been rapidly deteriorating. Private financial institutions like Visa and Mastercard suspended their operations in Russia, further isolating Russians from participating in the global economy, and the Western energy company British Petroleum announced that it would liquidate its holdings in Russian energy companies and suspend its operations in Russia.

Blinken affirmed that Western sanctions were drastically impacting the Russian economy.

He said, “The impact of the sanctions is already devastating. The ruble is in freefall. Their stock market’s been shuttered for almost a week. We’re seeing a recession set in Russia. Consumers aren’t able to buy basic products because companies are fleeing Russia, so it’s having a big impact.”