The nation’s top diplomat says that Ukraine will join NATO at some point in the future, an assertion probably intended to reassure Ukrainian officials but that also caused some ruffled feathers in Moscow and alarm among some U.S. lawmakers.

Speaking at NATO headquarters in Brussels alongside Ukrainian Foreign Minister Dmytro Kuleba following an event to mark treaty organization’s 75th anniversary, Secretary of State Antony Blinken said that support among member nations for Ukraine as it continues to defend itself against Russia’s unlawful and unprovoked invasion remains “rock solid.”

“We’re also here at NATO to talk about the summit that’s upcoming in the summer in Washington, celebrating the 75th anniversary of the Alliance. Ukraine will become a member of NATO. Our purpose of the summit is to help build a bridge to that membership and to create a clear pathway for Ukraine moving forward,” Blinken said.

Kuleba said that he’s aware that the conditions for Ukraine’s acceptance into the defense pact would require some further steps than just Blinken’s declaration, but that it should happen “sooner, rather than later.”

“We believe that Ukraine deserves to be a member of NATO,” he said. “So we will be looking forward to the outcome of these deliberations.”

Blinken’s announcement was not met with support from Russian officials. Former Russian President and current Security Council Deputy Chair Dmitry Medvedev said NATO troops in Ukraine would be treated “as enemies.”

“And not just enemies, but as elite detachments, Hitler’s SS punishers. And there can only be one rule for these overseas lice, who, unlike the unfortunate Ukrainians, were not forced to go to war: no prisoners taken! And for each NATO fighter killed, blown-up, or burned there must be a maximum reward. And no giving the bodies back. Let the relatives abroad suffer,” Medvedev said via the social media app formerly known as Twitter.

Our NATO friends have got a new mantra. Now they are collectively saying that intervention in “Ukraine” is not in plans. Just some troops will enter an area near Lvov and maybe Kiev to relieve the Ukrainian army. Kind of, doing housekeeping and organising; training; bringing…

— Dmitry Medvedev (@MedvedevRussiaE) April 4, 2024

Republicans from the House and Senate responded with alarm, suggesting that allowing Ukraine to join NATO while it’s actively engaged in a defensive war with Russia would inevitably mean the treaty’s Article 5 would trigger and draw the globe into a third world war.

“This is completely irresponsible. Ukraine should not join NATO, and to invite them during a war is to invite our nation into war. Do you want American ground troops in Ukraine? If not, we must push back against the idea that Ukraine should join NATO,” U.S. Sen. J.D. Vance said.

This is completely irresponsible. Ukraine should not join NATO, and to invite them during a war is to invite our nation into war.

Do you want American ground troops in Ukraine? If not, we must push back against the idea that Ukraine should join NATO. https://t.co/FkpPFZxbyP

— J.D. Vance (@JDVance1) April 4, 2024

“Making Ukraine a member of NATO means that the U.S. will be going to war against Russia as mandated by Article 5. 70% of Americans are AGAINST this!! All we want is our own border secured, but Ukraine is more important to them. The start of WWIII,” U.S. Rep Marjorie Taylor Greene said.

Making Ukraine a member of NATO means that the U.S. will be going to war against Russia as mandated by Article 5.

70% of Americans are AGAINST this!!

All we want is our own border secured, but Ukraine is more important to them.

The start of WWIII..

pic.twitter.com/QrBCYvcY2H

— Rep. Marjorie Taylor Greene (@RepMTG) April 4, 2024

President Joe Biden, in a statement shared by the White House, used NATO’s 75th anniversary to express support for Ukraine but did not go as far as his Secretary of State.

“Allies have stepped up to support the brave people of Ukraine in the face of Russia’s vicious invasion—the largest war in Europe since World War II,” Biden said. “We must remember that the sacred commitment we make to our Allies—to defend every inch of NATO territory—makes us safer too, and gives the United States a bulwark of security unrivaled by any other nation in the world.”