US Treasury Secretary Janet Yellen will travel to Asia next week to meet with officials from Japan, South Korea and other G20 countries in a bid to rally support for capping Russian oil prices, the Treasury Department said.

This is Yellen's first visit to the Indo-Pacific region as Treasury secretary and comes amid persistent questions about how effective capping Russian oil prices is without the support of India and other countries now buying cheap Russian oil, Reuters reports.

Yellen will hold bilateral meetings in Tokyo on July 12-13, and then meet with G-20 financial officials in Bali from July 15-16, and then hold talks in Seoul on July 19, the Treasury Department said in a statement.

The trip is part of a broader drive to "reaffirm America's leadership role in the region and around the world," expand support for sanctions against Russia, and step up efforts to respond to China, the Treasury Department said in a statement.

The United States and other wealthy G7 countries - Britain, Canada, Germany, France, Italy and Japan, as well as the European Union - agreed last week to explore a ban on the transportation of Russian oil sold above a certain price.

As the European Union prepares to impose a phased embargo on Russian oil and ban marine insurance on all tankers carrying Russian oil, Yellen sees the restriction as a way to keep oil flowing and prevent a price spike that could trigger a recession.

Washington was proposing a price exemption that would lift the ban on marine insurance when the price cap was met, a senior Treasury Department official said.

The details of how to structure and implement such a restriction are still being worked out, the official said, and each country needs to choose its own approach.

Some European officials are skeptical about how well the restriction will work, especially in the absence of India, China and other countries that buy large volumes of Russian oil at a discount.

Washington is in talks with a growing number of countries about the restriction, a second official said, citing good progress across the board.

Work with India will continue in the coming weeks, the official said.