By Nikunj Ohri and David Lawder

NEW DELHI (Reuters) -U.S. Treasury Secretary Janet Yellen said on Friday the United States was willing to work with India to help craft a communique at the end of the Group of 20 Summit in New Delhi over the weekend, but it would be a challenge.

"So I understand that this is challenging to craft such language, but I know the negotiators are discussing it, and working hard to do so and we stand ready certainly to work with India to try to craft a communique that successfully addresses this concern," Yellen told reporters at a briefing.

Analysts say deeper and more entrenched divisions over Russia's war in Ukraine risk derailing progress on issues such as food security, debt distress and global cooperation on climate change when the world's most powerful nations meet this weekend in New Delhi.

In her prepared comments, Yellen said she will work to build support to increase lending resources for the International Monetary Fund and the World Bank to help member countries deal with multiple global challenges, including new IMF quota resources.

She will seek to build G20 support for an "equi-proportional" increase in IMF quota funds paid-in by member countries, which would increase IMF lending resources, but not immediately change its shareholding structure.

At the briefing, Yellen said there was significant progress made on international debt relief efforts.

"International debt and providing relief to countries that are overindebted partly because of the impact of Russia’s war against Ukraine, but also the high interest rate environment, I believe we're beginning to make significant progress there. So I do see the G20 as a very effective forum," she said.

Yellen also said the United States has asked the U.S. Congress for permission to lend $21 billion to IMF trust funds, including one for the poorest countries, which "desperately needs more resources."

She highlighted progress on efforts over the past year by the World Bank and other multilateral development banks to vastly expand lending resources and help tackle climate change, pandemics and other global crises.

Near-term balance sheet changes under consideration could unlock an additional $200 billion over the next decade, she said.

More resources could come from medium-term steps recommended by a G20 capital adequacy review, including the use of callable capital that is pledged, but not paid-in, to back lending.

"Those are crucial additional resources for reducing poverty, advancing global health security and combating climate change," Yellen said.

The U.S. Treasury chief also said she will work to strengthen international support for Ukraine at the G20 gathering, saying it was "critical that we continue to provide timely economic assistance" through such measures as the IMF's $15.5 billion Ukraine loan program and the European Union's proposed 50 billion-euro support package through 2027.

"Even without Russia's active participation and the tensions the war has created, I still see that G20 is highly effective," Yellen said.