Biden, Allies Aim to Project United Front Against Russia at NATO Meeting

The U.S. and EU imposed the biggest coordinated package of sanctions ever levied against a major economy in the immediate aftermath of Russia’s invasion of Ukraine, and they have since expanded those measures.

National security adviser Jake Sullivan said Tuesday that Mr. Biden would join allies in imposing further sanctions on Russia and tightening the existing sanctions. Mr. Sullivan didn’t offer details on what he said would be a joint announcement Thursday.

According to U.S. officials and documents viewed by The Wall Street Journal, Mr. Biden is preparing to announce sanctions on more than 300 members of the Russian State Duma as soon as Thursday. The sanctions will be announced in coordination with the European Union and members of the G-7, U.S. officials said.

Mr. Sullivan also said Mr. Biden would “work with allies on longer-term adjustments to NATO force posture on the eastern flank.” There also would be joint action on enhancing European energy security and reducing European dependence on Russian gas, Mr. Sullivan said, as well as additional U.S. contributions to the humanitarian response.

“The president is traveling to Europe to ensure we stay united, to cement our collective resolve, to send a powerful message that we are prepared and committed to this for as long as it takes, and to advance our response on all three critical fronts that I’ve described: helping the Ukrainian people defend themselves, imposing and increasing costs on Russia, and reinforcing the Western alliance,” Mr. Sullivan said.

European diplomats say additional measures under discussion include potentially limiting Russian ships’ ability to call at European ports.

In addition to targeting Russia with sanctions, the U.S. and EU aim to reinforce their alliance by resolving longstanding disputes and aligning policies in other areas, such as trade and technology. Officials hope to announce on Thursday measures to resolve a legal fight over how digital data about European citizens is handled in the U.S. by American companies such as global tech giants. Failure to resolve the complex legal fight, which has run since 2015, could interrupt data flows across the Atlantic. It remains unclear if terms of a deal can be agreed during Mr. Biden’s visit, said a person familiar with the talks.

As the war has continued, more rounds of sanctions have shown some differences in the approaches taken by the U.S., U.K. and EU, including over energy. The U.S. and U.K. have banned Russian oil imports. Support for an EU-wide ban on the purchase of Russian oil is growing inside the bloc, but several members, including Germany, remain reluctant to support it.

The sanctions that began rolling out following Russia’s Feb. 24 invasion were made possible by increasing cooperation between the U.S. and EU on a number of issues over the past year, including the environment and trade, officials from both sides have said. A truce in the 17-year trade fight over subsidies to

Boeing Co.

and

Airbus SE,

announced during a visit to Brussels Mr. Biden made in June, facilitated trans-Atlantic cooperation on sanctioning Russia’s aviation sector, according to U.S. and EU officials.

Work implementing and expanding Russia sanctions has in turn made it easier for the U.S. and EU to align on future sanctions, officials say. Each side now better understands the other’s regulations in areas such as finance and export controls, and the Biden administration made a special effort to enlist Europeans in drafting Russia sanctions to ensure buy-in. Past U.S. efforts to sanction third countries, such as Cuba, Iran and Venezuela, have become sources of conflict with the EU because Europeans considered rules the U.S. imposed to exceed its legal power.

After Brussels, Mr. Biden is scheduled to travel to Poland, a U.S. ally that has seen an influx of more than two million refugees fleeing the violence in Ukraine. Mr. Biden will meet with Polish President

Andrzej Duda

on Saturday. Administration officials have said assisting Poland with the refugee crisis will be a key part of the discussions during Mr. Biden’s stop in Warsaw. Polish officials have pushed Washington on the issue.

Mr. Biden’s trip to Europe comes days after Russia’s foreign ministry warned relations between Moscow and Washington were “on the verge of a rupture.” Moscow summoned U.S. Ambassador John Sullivan on Monday to hand him a note of protest over Mr. Biden’s recent comment calling Mr. Putin a war criminal.

The U.S. president also recently announced a total of more than $1 billion in new military assistance to Ukraine’s government. The package included military equipment the U.S. says the Ukrainians need the most, including portable Javelin antitank systems and Stinger antiaircraft systems. For the first time, the U.S. is supplying Ukraine with lethal drones, tube-launched Switchblades. The funding was part of $13.6 billion allotted for helping Ukraine in a government spending bill that Mr. Biden signed last week.

The EU is close to approving another €500 million (about $551 million) in funding for its member states to cover the cost of arms and other equipment they send to Ukraine, which would take the total to €1 billion.

Ukrainian President

Volodymyr Zelensky

last week addressed Congress by video, calling on the U.S. to increase aid to his country, including by imposing a no-fly zone over it. Mr. Biden has rejected such a move, citing the logistical challenges and the risk of coming into direct conflict with the Russian military.

The U.S. has tried to orchestrate a transfer to Ukraine of Soviet-built MiG-29 jet fighters now owned by Poland, but Warsaw and Washington have been unable to agree on terms of a transfer to Kyiv.

—Laurence Norman and Catherine Lucey contributed to this article.

Write to Tarini Parti at Tarini.Parti@wsj.com and Daniel Michaels at daniel.michaels@wsj.com