By Steve Holland

WASHINGTON U.S. President Joe Biden's national security adviser, Jake Sullivan, is traveling to Denmark this weekend to participate in a meeting about Ukraine which may include some countries that have refused to condemn the invasion.

The talks in Copenhagen are being organized by Ukraine "to discuss basic principles of peace," a U.S. official said on Friday.

India, South Africa and Brazil were among the countries invited but it was unclear yet whether they were attending, a source familiar with the matter said. All three have not condemned Russia's invasion of Ukraine.

Western countries that back the war have also been invited.

The U.S. official said Ukraine invited a variety of countries and Denmark agreed to host the meeting in Copenhagen. It will include national security advisers and political directors from various countries invited.

The session is considered an informal gathering and not a formal summit. No specific outcomes and joint communiques are expected to come out of it.

Indian Prime Minister Narendra Modi, currently on a state visit to Washington, discussed the Ukraine war with U.S. President Joe Biden in talks on Thursday. His country has been reliant on Russian oil.

A joint statement from the two leaders said Biden and Modi expressed their "deep concern over the conflict in Ukraine and mourned its terrible and tragic humanitarian consequences."

"Both countries further pledge to render continuing humanitarian assistance to the people of Ukraine. They called for respect for international law, principles of the UN charter, and territorial integrity and sovereignty. Both countries concurred on the importance of post-conflict reconstruction in Ukraine," their statement said.

(Reporting By Steve Holland; editing by Jonathan Oatis)