BRUSSELS—Republican Senator John McCain revealed he hasn’t met the President Donald Trump in person since he took office, and he urged Trump to reach out to his opponents—Democratic and otherwise—ala Ronald Reagan if he wants to repeal Obamacare.

“Do some outreach. Get to know some of these Democratic leaders,” he said. “You can find common ground.” McCain said he’d met Trump “some years ago” when he was a businessman, but had not met him since. McCain said he did speak “almost daily” to National Security Adviser Lt. Gen. H.R. McMaster and Defense Secretary Jim Mattis, however.

“He doesn’t seem to be that upset that he’s not talking to him,” said German Marshall Fund’s Derek Chollet, a former Obama Pentagon official. “He’s trying to run U.S. defense policy through Mattis and effectively ignore Trump.”

The White House did not immediately respond to requests for comment.

The senior Republican and vociferous Trump critic said Trump’s tweet storms had caused “a great deal of uncertainty” about who advises the president. “Who drives the tweets at 6am in the morning?” he said, speaking at the German Marshall Fund’s Brussels Forum. He also expressed concerns, as head of the Senate Armed Services Committee, about the Trump campaign’s alleged ties to Moscow, and repeated his call for an independent committee to investigate such matters after House Intelligence Chairman Devin Nunes disclosed that he thought Trump’s communications may have been inadvertently listened to by the FBI, without sharing that with other committee members or disclosing his source. “I have significant concerns about the intelligence committee's ability to get to the bottom of this issue,” McCain said. “We need a select committee.”

However, McCain emphasized that ongoing controversy shouldn’t prevent the president from ever meeting with Russian counterparts.

“There’s nothing wrong with meetings,” the senator said. “At the height of the Cold War, (U.S. President) Ronald Reagan and (Soviet leader) Leonid Brezhnev met.” The proponent of Trump’s defense spending boost said the Trump needed to go to the meeting with a “strong hand” including “strong and growing military capabilities.”

—Kimberly Dozier