WATCH: House Speaker Nancy Pelosi condemns Putin during weekly news briefing

WASHINGTON (AP) — House Speaker Nancy Pelosi said Wednesday that Russian aggression toward Ukraine is “an attack on democracy,” vowing that the U.S. will stand united with its allies around the world in swiftly imposing sanctions on Russia and ensuring financial and political support for an independent Ukraine.

Watch the event in the player above.

Pelosi, who returned to the Capitol from a diplomatic overseas trip, compared the aggression to Russia’s intervention in the United States’ own democratic process during the 2016 election.

“There will be a price to pay for Vladimir Putin,” she said, flanked by lawmakers who had joined her delegation at the annual security conference in Munich.

Pelosi said the Russian president is one of the richest men in the world and warned that the sanctions being imposed by the U.S. and its allies are only the start of what is possible to inflict financial pain on his regime. “We’re doing this together,” she said.

For now, the U.S. Congress is largely backing President Joe Biden’s decision to slap sanctions on Russia, a rare but fragile bipartisan response to the most daunting foreign policy crisis the nation has faced in a generation.

But the next steps remain highly volatile.

With isolationist impulses rising at home, Congress has no appetite for war. And Republican critics of the Biden administration — and even some Democrats — want the White House to go even tougher with swifter and more severe sanctions on Russia.

Republican leaders have sought to steer the conversation to their preferred terms, as the party whose defense hawks once led the nation on the national security front. But it’s not at all clear whether today’s GOP can keep Republicans from tapping into an impassioned non-interventionist strain unleashed by Donald Trump’s “America First” approach.

It was Trump who sought to strip protections for Ukraine from the Republican Party platform for the 2016 election, and who was impeached by the House for abuse of power after he pressured the Ukrainian president to dig up dirt on Biden during the 2016 campaign. This week, Trump cheered on Putin as he massed military forces near Ukraine’s border and recognized the independence of its separatist regions in a move Biden and others warned is the start of an invasion of Ukraine.

Senate Republican leader Mitch McConnell, a longtime champion of NATO, spoke highly of the Western alliance this week, but some within his party are gravitating away from that traditional Republican position and toward Trump’s views.

McConnell said he wants to see Biden impose the “toughest possible sanctions.”

Still, most Republican senators are backing Biden’s sanctions on Putin, even if some are clamoring for more.

Republican Sen. Lindsey Graham of South Carolina, a sometimes Trump ally who is also one of the party’s leading defense hawks, used to globetrot with fellow GOP Sen. John McCain and invoked his late colleague this week in urging Biden to confront Putin more forcefully.

Graham said Congress should impose “sanctions from hell” on Putin and his regime when lawmakers return to work next week.

Pelosi said Russians need to understand what their leader is doing. “It’s stunning to see in this day and age, a tyrant roll into a country,” Pelosi said.

The Senate has bipartisan support for a robust sanctions package but after running into differences over the scope and timing of the response decided to shelve a vote as the White House pursued its own strategy.

Associated Press writer Farnoush Amiri contributed to this report.