Hillary Clinton is supporting President Obama's plan for closing the military prison at Guantanamo Bay, saying the move would "be a sign of strength and resolve."

"I support President Obama’s plan today to close the detention facility at Guantanamo Bay and finally close the door on this chapter of our history," she said in a Tuesday statement.

"Over the years, Guantanamo has inspired more terrorists than it has imprisoned. It has not strengthened our national security; it has damaged it."

Closing Guantanamo was one of Obama's earliest campaign promises in 2008, but Congress has blocked his efforts.

The president submitted a final plan to Congress to close the facility on Tuesday. But it was meet by immediate opposition from Republicans, who called it dead on arrival.

The Obama administration's plan would move detainees eligible for transfer to other countries. Other detainees would face prosecution. But the plans also call for moving between 30 to 60 detainees not eligible for those options to the United States.

The administration said the plan could cost up to $425 million, but would save more than $65 million per year in the long run. 

Clinton's statement came hours after her presidential rivals reacted to the proposal.

Her Democratic rival Bernie Sanders also backed Obama's plan while also delivering a shot at Clinton.

"Sanders was one of only three senators to vote in 2007 against barring the transfer of Guantanamo detainees to America," his statement read. "Then-Sen. Hillary Clinton voted for the amendment that kept the prison open."

That 2007 measure was a "sense of the Senate" vote that specifically warned against releasing Guantanamo prisoners "into American society" or "facilities in American communities and neighborhoods."

Clinton's statement didn't respond to Sanders, but touted her own history of pushing to close the facility. It notes that she cosponsored legislation to do so and highlights her work as secretary of State to resettle Guantanamo prisoners.