President Biden departs the White House on Wednesday for his trip to Brussels and Poland, where he plans to work to keep allies unified on their response to Russia's invasion of Ukraine.

Caption

President Biden departs the White House on Wednesday for his trip to Brussels and Poland, where he plans to work to keep allies unified on their response to Russia's invasion of Ukraine. / AFP via Getty Images

Updated March 23, 2022 at 9:22 AM ET

President Biden left for Brussels on Wednesday, a trip aimed at presenting a united front against Russia as its brutal war against Ukraine drags toward the one-month mark.

He plans to make announcements with allies and European partners about new sanctions for Russia and new humanitarian aid for Ukraine and the millions of refugees fleeing the fighting.

"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," said Jake Sullivan, Biden's national security adviser.

"There will be hard days ahead in Ukraine," Sullivan warned. "This war will not end easily or rapidly."

On his way out of the White House on Wednesday, Biden declined to talk about what he planned to say to world leaders. "All I have to say, I'm going to say it when I get there," he told reporters. The White House has said Biden will take reporters' questions on Thursday.

There's a lot of symbolism in this moment

President Biden and other NATO leaders pose for the traditional family photo during a summit at the alliance's headquarters in June.

Caption

President Biden and other NATO leaders pose for the traditional family photo during a summit at the alliance's headquarters in June. / Pool/AFP via Getty Images

Seeing Western leaders standing side-by-side in Brussels will send a powerful message to Europeans alarmed at Russia's attack on Ukraine — and a message to Russian President Vladimir Putin about the strength of the NATO alliance, said Jim Townsend, a former deputy assistant secretary of defense for European and NATO policy.

"That family photo is going to show everyone that these guys are unified," said Townsend, now at the Center for a New American Security think-tank. "That family photo is one of the most important deliverables coming out of the meeting at NATO."

NATO is looking at whether it needs to bolster forces on its eastern flank

A woman offers Polish donuts to U.S. Army soldiers from the 82nd Airborne Division on March 7 in Przemysl, Poland. The U.S. has sent thousands of troops to Poland to bolster NATO forces.

Caption

A woman offers Polish donuts to U.S. Army soldiers from the 82nd Airborne Division on March 7 in Przemysl, Poland. The U.S. has sent thousands of troops to Poland to bolster NATO forces. / Getty Images

Allies closest to Russia — including Romania and the three Baltic states — have pressed NATO and the United States to boost troops in their countries. Sullivan said Biden plans to discuss whether more troops are needed in the region, particularly over the long term.

Russia's aggression has prompted NATO leaders to reexamine the long-term strategic direction of the alliance, refocusing on Russia only months after Biden had pushed them to focus more on new challenges posed by China and climate change, Townsend said.

"It's the old playbook," he said. "You can hear the tires screeching from here."

At the same time, Ukrainian President Volodymyr Zelenskyy, who will speak to the NATO meeting from Ukraine on Thursday, has been pushing for more defensive support from the alliance.

Ian Lesser, the vice president and executive director of the German Marshall Fund of the United States, said there may not be much appetite for that.

"Much of the support to Ukraine that has been delivered so far is really being delivered among a coalition of nation states — a coalition of the willing within NATO — but not necessarily as NATO's action, per se," Lesser said.

"As time goes on, there's an open question as to whether Russia will continue to tolerate the supply lines" of arms transfers and fuel deliveries to Ukraine being organized from NATO territory, Lesser said.

White House national security adviser Jake Sullivan briefs reporters ahead of President Biden's trip to Brussels.

Caption

White House national security adviser Jake Sullivan briefs reporters ahead of President Biden's trip to Brussels. / Getty Images

There will be new sanctions on Russia — and more enforcement

The U.S. and other major economies have frozen reserves held by Russia's central bank. Some major Russian banks have been shut out of SWIFT, a system used by the world's banks for transactions. Officials and oligarchs close to Putin have also seen their assets affected by sanctions.

Sullivan said Biden and allies are prepared to announce a new package of sanctions. They're also going to announce new measures to crack down on efforts to evade existing sanctions, including "any attempt by any country to help Russia basically undermine, weaken, or get around the sanctions," he said.

There have been carve-outs in sanctions for transactions related to oil and gas, the lifeblood of Russia's economy. While the United States has banned imports of Russian oil, European partners depend on Moscow for energy.

Biden is set to announce "joint action on enhancing European energy security and reducing Europe's dependence on Russian gas at long last," Sullivan said, without providing details.

Biden will announce more humanitarian aid for Ukraine

A woman waits for a bus at Przemysl train station in Polan after travelling on a train from war-torn Ukraine on March 22.

Caption

A woman waits for a bus at Przemysl train station in Polan after travelling on a train from war-torn Ukraine on March 22. / Getty Images

More than 3.5 million Ukrainians have fled the fighting in their country. Biden will travel to Warsaw and meet with Polish President Andrzej Duda. In Poland, he will visit U.S. troops stationed there, and talk to humanitarian experts, Sullivan said.

"He will announce further American contributions to a coordinated humanitarian response to ease the suffering of civilians inside Ukraine and to respond to the growing flow of refugees," he said.

Russia's relationship with the G-20 and China will be in focus

After Russia annexed Crimea in 2014, it was kicked out of what was then known as the G-8 group of major economies. Now there are suggestions that Russia be excluded from the G-20 as well.

Asked about the G-20 debate, Sullivan said: "We believe that it cannot be business as usual for Russia in international institutions and in the international community." But he noted Biden would want to consult allies and partners "before making any further pronouncements."

Biden does plan to talk to European partners about China's ties to Russia, Sullivan said. The administration is worried Beijing will provide economic or military help to Moscow. It's something Biden discussed with Chinese leader Xi Jinping last week.

European Union leaders are planning their own summit with Xi on April 1, Sullivan noted. "This will be an opportunity — Thursday — for the United States and our European partners to coordinate closely on what our message is," he said.

Copyright 2022 NPR. To see more, visit https://www.npr.org.