Sen. John McCain on Sunday said President Trump's trip to Saudi Arabia this weekend sent a strong message to Iran that the U.S. and its allies are ready to block Iran's efforts to destabilize the region.

"There's no doubt that if we're going to impede the Iranian's continued efforts to exert, certainly, significant strength in the region that this is an important step forward," the Arizona Republican said on "Fox News Sunday."

Trump's trip to Saudi Arabia was also necessary to patch up relations that had soured under the Obama administration, he said.

"I think that the Sunni-Arab world, particularly our traditional friends there, are encouraged because of the very strained, if not estranged, relations between the previous administration," McCain said. "And so I think it's successful, I think it's important."