Denmark on Saturday hosts a meeting organised by Ukraine bringing together several nations -- including those who have remained neutral on the Russian invasion -- to discuss a path towards peace.
Few details have leaked about the meeting. However a Western official speaking on condition of anonymity said that White House national security adviser Jake Sullivan would attend.
The meeting in Copenhagen aims to discuss ways of achieving a "just and lasting peace" in Ukraine, the source said.
The invitees include top security officials from the United States, the European Union and other countries that have backed Ukraine since Russia invaded last year, as well as those that have not condemned the invasion, the source added.
They did not specify which countries.
"We have worked very hard inside (the) G7 on a peace formula," said a European diplomatic source, also speaking on condition of anonymity.
"So the idea is to go beyond that and involve key actors like Brazil and India. We frankly expect and wish that China will be there."
The meeting was first reported by the UK's Financial Times.
It cited sources familiar with the plans as saying the meeting could include officials from Brazil, India and South Africa, although the list of attendees had not been finalised.
Those three states, along with China, are part of the BRICS bloc with Russia, and have not joined the West in sanctioning Moscow.
Indian Prime Minister Narendra Modi visited Washington on Thursday, where he said in a joint statement with U.S. President Joe Biden, that he backed the "territorial integrity" of Ukraine.
The discussions in Denmark are expected to be informal, without a resulting official statement.
But they are seen as a milestone on the path to a peace summit organised by Ukrainian President Volodymyr Zelensky.
A date has not yet been set for this summit, which could be held in Copenhagen or Paris in the coming months, but the EU has said "substantial" preparation was necessary.
"We consider that it is fundamental to have as broad support as possible from the international community," said the European diplomat.
Obtaining new support is crucial for Kyiv, whose counteroffensive, which began in early June, has so far only seen modest gains.
This week, foreign donors at an international conference in London pledged 60 billion euros ($66 billion) in new financial support for the reconstruction of Ukraine.
