U.S. President Joe Biden walks to board Marine One, before traveling to Rehoboth Beach, Delaware for the weekend, on the South Lawn of the White House in Washington, U.S., March 18, 2022.
U.S. President Joe Biden walks to board Marine One, before traveling to Rehoboth Beach, Delaware for the weekend, on the South Lawn of the White House in Washington, U.S., March 18, 2022. Reuters / ALEXANDER DRAGO

President Joe Biden flew to Brussels on Wednesday for emergency talks with European leaders about the war in Ukraine, carrying with him plans for more sanctions that sources said include members of the Russian parliament.

Biden's trip includes talks in Brussels with NATO and European leaders and a visit to Warsaw for consultations with Polish President Andrzej Duda.

On Thursday, Biden 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.

Speaking to reporters on the Air Force One flight to Brussels, White House national security adviser Jake Sullivan said Biden will announce a package of Russia-related sanctions on political figures and oligarchs on Thursday.

He said G7 leaders will also agree on Thursday to coordinate on sanctions enforcement and plan to issue a statement.

Amid concerns about Europe's dependence on Russian energy, Sullivan said the topic will be an important one for Biden and the allies and that officials will have more to say on Friday about European energy issues.

After Biden warned Chinese President Xi Jinping on Friday not to provide material support to Russia in its war against Ukraine, Sullivan said the United States has not yet seen evidence of Beijing sending aid to Moscow.

"But it's something we're watching every day," he said.

Western leaders have grown increasingly concerned that Russian President Vladimir Putin will use chemical weapons or otherwise escalate tactics four weeks into an invasion where his troops have failed to capture a single major Ukrainian city.

Leaving the White House on Wednesday, Biden said Russia's use of chemical weapons in Ukraine is a risk.

"I think it's a real threat," he said.

Biden and his team have been developing plans to impose sanctions on members of the Duma, Russia's parliament, in retaliation for Russia's invasion of Ukraine, according to two sources familiar with the situation.

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.

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

In addition to imposing fresh sanctions on Russia, Biden will work with U.S. allies to tighten existing sanctions, he said.

Sullivan also said Biden will discuss with allies in Brussels "how to deal with the rhetoric and commentary on potential use of nuclear weapons" by Russia. The United States has not changed its nuclear posture, he said.

In recent days, Russia and Western governments have traded accusations over the possibility of a chemical weapons attack in Ukraine without producing evidence to back their concerns.

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 edgy allies.

During his visit to Poland, a NATO member, 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.