The gathering of world leaders at the IMF and World Bank's spring meetings brings an "opportunity" for progress in tapping immobilized Russian assets to aid Ukraine, a senior US Treasury official said Monday.

Leaders including Treasury Secretary Janet Yellen will represent the United States at the International Monetary Fund and World Bank talks this week in Washington -- covering issues including the impact of Iran's recent attack on Israel.

In particular, conversations are set to "include ways to unlock the value of immobilized Russian sovereign assets to support Ukraine's continued resistance and long-term reconstruction," the Treasury official told reporters.

The comments come on the back of mounting calls in Washington and Europe to set up a fund for Ukraine using billions of dollars in Russian bank accounts, investments, and other assets frozen by the West over Moscow's invasion of its neighbor in 2022.

On Monday, the Treasury official also told reporters: "I want to condemn in the strongest possible terms Iran's attack on Israel over the weekend."

Calling Iran and proxies a "destabilizing force" in the Middle East, the official added that recent events are due to be a significant topic of conversation in meetings while President Joe Biden leads an international response.

On Wednesday, Yellen will have a meeting with counterparts from Japan and South Korea to coordinate on issues ranging from sanctions to secure supply chains, according to the Treasury.

Yellen will also stay focused on managing US relations with China, following her recent travel to the country where she raised concerns about its excess industrial capacity.

"We hope to make further headway on our shared work on sustainable finance," the Treasury official said.

The Treasury Department is set to host a fourth meeting of the US-China economic and financial working groups this week as well.

The aim is to start exchanging more detailed data and try to make progress on issues like balanced economic growth -- including the issue of overcapacity.