Defense Secretary Pete Hegseth on Wednesday told NATO it is “unrealistic” to hope for a return to the version of Ukraine’s borders that existed before Russia annexed Crimea in 2014.

Hegseth further said that the U.S. “does not believe that NATO membership for Ukraine is a realistic outcome for a negotiated settlement.”

“We want, like you, a sovereign and prosperous Ukraine,” Hegseth said during a trip to NATO’s headquarters in Brussels. “But we must start by recognizing that returning to Ukraine’s pre-2014 borders is an unrealistic objective.”

The defense secretary said chasing that “illusionary goal will only prolong the war and cause more suffering.”

Hegseth’s comments represent the administration’s first explicit acknowledgement of support for a peace deal that would involve Ukraine ceding territory to end the war as quickly as possible. 

The defense secretary addressed fears that negotiations could embolden Russian President Vladimir Putin by saying that “a durable peace for Ukraine must include robust security guarantees to ensure that the war won’t begin again.”

However, he said that peace would not involve U.S. troops deployed to Ukraine.

The U.S. government has provided $65.9 billion in military assistance to Ukraine since Russia invaded Ukraine three years ago. Trump campaigned on ending the war and having European countries step in to provide more assistance to Ukraine.

Hegseth told NATO he had traveled to Brussels  to “directly and unambiguously express that stark strategic realities prevent the United States from being the primary guarantor of security in Europe.” 

“The United States faces consequential threats to our homeland. We must — and we are — focusing on securing our own borders,” he said.

Hegseth said Trump would look to further negotiations by unleashing American energy production to take away from Russia’s exports that help fund the war.