U.S. Treasury Secretary Janet Yellen said on Tuesday that it is “urgent” for the G7, the group of seven leading industrialized nations, to seize some $285 billion worth of frozen Russian assets and redirect the funds to Ukraine.

Pressure has been mounting on the United States and Europe to make use of the funds. Although Yellen said that there isn’t a “preferred strategy” to address the issue, she added that the G7 makes up more than half the global economy and all action should be taken jointly.

Yellen said during a news conference in Sao Paulo, Brazil, that the U.S. and its allies are evaluating ways to move the assets and the risks associated with using them. G7 leaders asked for solutions to be presented in June.

While speaking to journalists in Brazil, Yellen said, “It is necessary and urgent for our coalition to find a way to unlock the value of these immobilized assets to support Ukraine’s continued resistance and long-term reconstruction.”

Yellen’s comments come before the G20, comprising the 20 biggest economies, is set to meet and discuss the issue on Wednesday and Thursday. G7 officials say they will meet on the sidelines of the meeting in Brazil to discuss ways to support Ukraine.

While many have been calling on the West to redirect frozen funds to Ukraine, some fear that taking such actions against Russia would undermine currencies like the dollar, the euro or the Japanese yen.

Yellen responded to the concerns, saying that a major shift from currencies is “extremely unlikely,” citing the uniqueness of the situation.

She added that there is a “strong international law, economic and moral case for moving forward,” with redirecting the assets, and that it would show Russia that Ukraine’s allies will stand strong in solidarity.

She also said that strong joint action could provide an incentive to Moscow to negotiate peace with Ukraine, and that the country needs approximately $486 billion to recover from the war.

Some information for this report came from Reuters and Agence France-Presse.