President Joe Biden departs for Brussels on Wednesday for talks with European leaders about Russia's invasion of Ukraine, carrying with him plans for more sanctions on Moscow that sources said include members of the Russian parliament.

Biden leaves the White House at 8:40 a.m. EDT on a trip that will include talks in Brussels with NATO and European leaders and a visit to Warsaw for consultations with Polish President Andrzej Duda.

Two sources familiar with the situation said Biden and his team were developing plans to impose sanctions on members of the Russian parliament, the Duma, in retaliation for Russia's invasion of Ukraine. The sanctions are expected to be announced on Thursday.

The Wall Street Journal said 300 members of the Duma could face sanctions.

A White House spokesperson said "no final decisions have been made about who we will sanction and how many we will sanction."

"We will have additional sanctions measures to announce that will rolled out in conjunction with our allies on Thursday when the president has the opportunity to speak with them," the official said.

White House national security adviser Jake Sullivan told reporters on Tuesday that Biden on Thursday will attend an emergency NATO summit, meet with G7 leaders and address the 27 leaders of the European Union at a session of the European Council.

Biden will coordinate on the next phase of military assistance to Ukraine, said Sullivan.

In addition to imposing fresh sanctions on Russia, Biden will work with U.S. allies to tighten existing sanctions to "crack down on evasion and to ensure robust enforcement," Sullivan said.

Biden has vowed not to engage in direct conflict with Russia but has pledged the United States will defend all NATO territory. He has ordered more U.S. troops to NATO's eastern flank to reassure those edgy allies.

During his visit to Poland, Biden will visit U.S. troops and meet with experts involved in the humanitarian response to helping hundreds of thousands of Ukrainians who have fled their country and those who remain their.

Russian President Vladimir Putin intends to attend a G20 summit being hosted by Indonesia later this year, Russia's ambassador in Jakarta said on Wednesday, following calls by some members for the country to be barred from the group.

"Not only G20, many organisations are trying to expel Russia....the reaction of the West is absolutely disproportional," ambassador Lyudmila Vorobieva told a news conference on Wednesday.

The United States and its Western allies are assessing whether Russia should remain within the Group of Twenty (G20) grouping of major economies following its invasion of Ukraine, sources involved in the discussions told Reuters.

The likelihood that any bid to exclude Russia outright would be vetoed by others in the club - which includes China, India, Saudi Arabia and others - raised the prospect of some countries instead skipping G20 meetings this year, the sources said.