President Trump and Israeli Prime Minister Benjamin Netanyahu speak at a news conference on Feb. 15 at the White House in Washington. (Pablo Martinez Monsivais/Associated Press)

A growing roster of Republicans and Democrats on Capitol Hill say they believe President Trump’s pugnacious rhetoric and unpredictable behavior threaten to diminish the United States’ standing around the world, do real damage to fragile diplomatic ­relationships and even weaken global stability.

Lawmakers are speaking in increasingly urgent tones about Trump’s unusual foreign policy statements and his tendency to pick fights with domestic and international figures. They say it has taken a toll on the way key allies, foes and other foreign observers view the United States. Even members of Trump’s own party are having difficulties vouching for him.

“A country’s more than one ­person,” said Sen. Marco Rubio (R-Fla.), when asked whether he is concerned that the president’s words have harmed the U.S. ­image. The senator, who dined Wednesday with Trump but has also criticized the president’s ­posture toward Russia, added: “There’s more than one voice in America.”

In a striking speech to international defense officials gathered Friday in Germany, Sen. John McCain (R-Ariz.) suggested that the survival of the Western world is at risk from some of the ideas Trump has embraced.

“The next panel asks us to consider whether the West will survive. In recent years, this question would invite accusations of hyperbole and alarmism. Not this year,” McCain said, according to prepared remarks delivered Friday at the Munich Security Conference. “If ever there were a time to treat this question with a deadly seriousness, it is now.”

(Sarah Parnass/The Washington Post)

McCain did not mention Trump, who did not attend the conference, by name. But it was clear that he was lamenting the policies and practices of the Trump administration — and their threat to global stability. He imagined how disturbed the security conference’s founders would be. The forum was formed 50 years ago, at the height of the Cold War, to bring world powers together to discuss and further global stability.

“They would be alarmed by the hardening resentment we see toward immigrants, and refugees, and minority groups, especially Muslims,” McCain said. “They would be alarmed by the growing inability, and even unwillingness, to separate truth from lies. They would be alarmed that more and more of our fellow citizens seem to be flirting with authoritarianism and romanticizing it as our moral equivalent.”

In an interview for Sunday’s “Meet the Press” with Chuck Todd, McCain was asked about Trump’s Friday tweet that the press is the “enemy of the American people.”

McCain warned that a free press is “vital” to “preserve democracy as we know it.”

“And without it, I am afraid that we would lose so much of our individual liberties over time. That’s how dictators get started,” McCain said, clarifying that he was not calling Trump a dictator but warning that dictators start by “suppressing free press” and “we need to learn the lessons of ­history.”

Top Republican congressional leaders have sought to curtail intraparty anxiety by noting that while much of what Trump says is unusual and troublesome, in practice, he is actually shaping up as a traditional GOP president. Trump’s supporters say he is still ironing out wrinkles as he adapts to being president. But others are losing patience with the Trump administration amid qualms about its approach to national security, the U.S.-Russian relationship and the risk to long-standing alliances the United States has cultivated with other nations.

Trump has come under heavy criticism for spearheading a temporary immigration ban on refugees and foreign nationals from seven majority-Muslim nations, which has been temporarily halted by a federal court. He has also drawn fierce blowback for disparaging critical stories about him as “fake news” and responding to a Fox News interviewer telling him Russian President Vladi­mir Putin is a “killer” by saying, “Do you think our country is so innocent?”

McCain, who said there is concern that “America is laying down the mantle of global leadership,” mentioned several Trump administration officials attending the conference — Vice President Pence, Homeland Security Secretary John F. Kelly and Defense Secretary Jim Mattis — as examples of officials committed to maintaining the country’s global role.

Democrats are less subtle. Among their top concerns: Trump’s charge that NATO is ­“obsolete,” which they say has struck a nerve among U.S. ­partners in the West.

“I think our allies are legitimately terrified that our president is not devoted to NATO, that he is supportive of European disintegration, that the approach that he wants to take with Russia will come at their expense,” said Rep. Adam B. Schiff (D-Calif.), the top Democrat on the House Permanent Select Committee on Intelligence.

Lawmakers in both parties were still reacting Friday and ­Saturday to Trump’s news conference Thursday, when he lashed out against the news media, the intelligence community and his critics — and defended advisers against claims of improper ­contacts with Russia.

Senate Minority Leader Charles E. Schumer (D-N.Y.) responded to a question about the news conference Friday by letting out a long sigh. A few minutes later, Senate Majority Leader Mitch McConnell (R-Ky.) wasn’t eager to talk about it.

“I don’t have any observation about that,” he said when asked whether it hurt or helped Trump’s ability to lead.

“We thought he was erratic; we’re learning just how erratic he really is,” Rep. Joseph Crowley (D-N.Y.), the chairman of the House Democratic Caucus, said in a C-SPAN interview with a Washington Post reporter recorded Friday. “If this past week’s press conference is any indication of how he’s going to conduct himself, I actually think it’s not just about House Democrats, but my House Republican colleagues: When do they show any sign of resistance to this administration?”

McConnell explained at a news conference Friday that while Trump’s Twitter attacks on various people don’t appeal to him, “What I am a fan of is what he’s been actually doing.” In an interview with The Post the day before, the GOP leader also pointed out that Trump has not relaxed sanctions on Russia — a good move, in his view — even though he has publicly weighed doing so.

But Sen. Christopher A. Coons (D-Del.), a member of the Senate Foreign Relations Committee, said Trump’s rhetoric has made a tangible and troubling difference. He said it has created a deep fear that Putin will try advancing more deeply into Eastern Europe, based on conversations he has had with leaders of Baltic states and other European nations.

“They are alarmed by nearly all of what President Trump has said, as a candidate, as the Republican nominee, as a president-elect, and as president, that suggests a misguided embrace of Vladimir Putin and a refusal to directly confront Russia’s organized campaign to undermine democracy,” Coons said.

Others were more forbearing. Sen. Mike Rounds (R-S.D.), who sits on the Senate Armed Services Committee, said Trump is “still having a conversation over the coffee table with the American public” as he decides which policies to implement.

“The traditional folks that work in government on a day-to-day basis in other countries are looking at this and shaking their head. But I think they’ll get used to it,” Rounds said.

Sen. Bob Corker (R-Tenn.), the chairman of the Senate Foreign Relations Committee, said he takes comfort in a belief that Mattis and Secretary of State Rex Tillerson hold more orthodox Republican views on Russia and can influence Trump on that front.

“They’re not our friend, okay?” Corker said of Russia.

While Corker and other ­Republicans have lauded members of Trump’s national security team, there is uncertainty about how it will look and operate moving forward. Michael Flynn recently resigned as Trump’s national security adviser amid revelations that he misled administration officials about his interactions with Russia. Trump is still trying to fill that post.

In his weekly address, Trump touted some accomplishments and interactions with foreign leaders, including meetings with Canadian Prime Minister Justin Trudeau and Israeli Prime Minister Benjamin Netanyahu. “We are not here for the benefit of bureaucrats, consultants or pundits. We are here to work for you and only for you, the American people,” Trump said.

At the other end of Pennsylvania Avenue, Sen. Jeff Flake (R-Ariz.) declined to say anything when asked about Trump’s impact. “I don’t want to comment on daily statements by the president,” he said.

Paul Kane, Ashley Parker and John Wagner contributed to this report.