 -- Following a series of moves by Donald Trump that showed a willingness to engage with controversial world leaders, a pair of Republican senators are speaking out against the president's actions.

Sens. Bob Corker, R-Tennessee, and John McCain, R-Arizona, voiced opposition Tuesday to Trump's recent phone call with Turkish President Recep Tayyip Erdogan, the invitation to Filipino President Rodrigo Duterte to visit the White House, and the president's response Monday that he would be "honored" to meet with North Korean leader Kim Jong Un.

"I'm not sure that sometimes the president takes into account what his words mean in other places around the world," said Corker, a Trump ally and the chairman of the Senate Foreign Relations Committee.

Corker suggested he was concerned about all such communications, including to Duterte and Kim, but specified that the phone call congratulating Erdogan on the April vote that substantially consolidated his power "had a very damaging effect" with America's allies.

On the invitation extended to Duterte to visit the White House, Corker said, "I think the president sometimes is being conversational and trying to show an openness and I think as time goes on he'll understand the gravity of actually having people come to the White House like that."

"[Duterte] is certainly not on the list of people that I would want to be one of the first people to come visit," Corker added.

McCain, the Senate Armed Services Committee chairman who has shown a willingness to critique the president -- who once addressed McCain's stay in a Vietnamese prisoner of war camp by saying, "I like people who weren't captured" -- also criticized Trump's overtures to authoritarian leaders around the globe.

"I disagree, obviously," he said. "I'm a Ronald Reagan Republican and [these actions are] not Ronald Reagan."