Sen. Mitt Romney on Thursday called for public hearings in the Senate to investigate President Donald Trump's decision to withdraw troops from Syria amid the news that Turkey has agreed to a five-day cease-fire in a deal brokered with the U.S.

The Utah Republican, who has been an outspoken critic of the Syria decision, delivered a sharp condemnation of the administration's withdrawal from the area near the country's border with Turkey. The retreat quickly led to a Turkish invasion resulting in civilian casualties and the displacement of those in the area.

Romney also decried the White House decision not to consult with lawmakers in the relevant foreign policy committees in Congress. Romney, who sits on the Senate Foreign Relations Committee, said he wants public hearings to start as early as next week.

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"I believe it's imperative that public hearings are held to answer these questions, and I hope the Senate is able to hold those hearings next week," Romney said in a Thursday floor speech.

"What we have done to the Kurds will stand as a blood stain in the annals of American history. America is diminished. Russia, Iran and [Syrian President Bashar] al-Assad are strengthened."

Romney's speech came about an hour after Vice President Mike Pence and Turkish President Recep Tayyip Erdogan negotiated a deal by which Turkey will pause military action in northeastern Syria for the next 120 hours as Kurdish fighters, known as the YPG, leave the area. The YPG previously allied with the U.S. to fight against the Islamic State group in Syria.

Pence announced that a permanent cease-fire will take effect once Kurdish troops leave the safe zone. When that happens, the U.S. will lift economic sanctions already imposed on Turkey.

Trump praised the deal shortly after Pence's announcement from Ankara. The president has wholeheartedly stood by his decision on troop withdrawals, arguing that he's fulfilling his promise to stop "endless wars." But the move has drawn widespread criticism from lawmakers in both parties.

"This is a great day for civilization. I am proud of the United States for sticking by me in following a necessary, but somewhat unconventional, path. People have been trying to make this 'Deal' for many years. Millions of lives will be saved. Congratulations to ALL!" Trump tweeted.

Romney said he hopes the agreement between Turkey and the U.S. is "honored" and brings an end to Turkey's "brutal killing."