President Barack Obama said Tuesday that he will revive his push to close the U.S. military prison at Guantanamo Bay, Cuba, a first-term campaign promise that a Democratic-led Congress rejected as impractical and potentially unsafe.

With a majority of Guantanamo's 166 detainees on a mass hunger strike, Obama said at a White House news conference that the existence of the facility damages the country's image abroad, costs too much money and undermines U.S. counterterrorism efforts by serving as a recruiting tool for militants.

"I'm going to go back at this," he said. "I'm going to re-engage with Congress to try to make the case that this is not something that's in the best interests of the American people."