U.S. President Donald Trump and first lady Melania Trump greet members of the U.S. military during an unannounced trip to Al Asad Air Base in Iraq on Dec. 26, 2018. (Xinhua/AFP)

WASHINGTON, Dec. 27 (Xinhua) -- U.S. President Donald Trump said Thursday that he has returned to the United States after an unannounced visit overseas to Iraq and Germany.

Trump tweeted that he had "just returned from visiting our troops in Iraq and Germany. One thing is certain, we have incredible people representing our Country -- people that know how to win!"

During his stay in Iraq, Trump defended his decisions to withdraw troops from Syria and let Secretary of Defense James Mattis leave earlier than scheduled, saying that regional nations in the Middle East shall take responsibility for their security and the United States shall not be "taken advantage of."

However, he promised not to pull U.S. forces out of Iraq, saying the country could be used as a place to "do something in Syria."

Trump has never been a fan of sending U.S. troops out for battles overseas. During his tour, he said that "we are spread out all over the world. We are in countries most people haven't even heard about. Frankly, it's ridiculous."

However, Richard Haass, head of the U.S. think tank Council on Foreign Relations, tweeted that it was "wrong to inject domestic politics into remarks, to not meet best-ever leaders of Iraq, and to articulate a vision of U.S. foreign policy that emphasized exit-strategies over all else and costs without mention of benefits."

"According to @realDonaldTrump, it is ridiculous U.S. troops are in places Americans have not heard of. I disagree," he said. "Most wars -- from WWII thru war on terror -- are in places that only get well known after the fact. Nothing ridiculous about such commitments."