U.S. President Donald Trump(L) delivers his State of the Union address to a joint session of Congress on Capitol Hill in Washington D.C., the United States, Jan. 30, 2018. (Xinhua/Yin Bogu)

WASHINGTON, Jan. 30 (Xinhua) -- U.S. President Donald Trump said in his first State of the Union address on Tuesday that he had signed an order to reexamine the U.S. military detention policy and to keep open the detention facilities at Guantanamo Bay in Cuba.

"In the past, we have foolishly released hundreds and hundreds of dangerous terrorists, only to meet them again on the battlefield -- including the ISIS leader, al-Baghdadi, who we had, who we released," Trump said.

"So today, I am keeping another promise," he said.

"When possible, we annihilate them. When necessary, we must be able to detain and question them. But we must be clear: Terrorists are not merely criminals. They are unlawful enemy combatants. And when captured overseas, they should be treated like the terrorists they are," he said.

"In many cases, for them, it will now be Guantanamo," Trump said.

Only 41 detainees now remain in the facility, set up in 2002 as part of the U.S. war on terror. Critics say the center has been plagued by crimes of torture.

Hundreds of detainees were transferred to sites in the United States or sent to their home countries under President Barack Obama, who failed to close the prison center.

Last year, Trump said he would consider sending terror suspects who allegedly committed crimes on U.S. soil to the military prison.

Earlier this month, dozens of activists held a rally outside the White House to protest against the Guantanamo Bay prison, urging an end to "indefinite detention."