Pennsylvania Republican Sen. Patrick Toomey said Defense Secretary Gen. James Mattis’ resignation over ideological differences with President Trump shows that the president’s foreign policy views diverge from those held by the majority of Americans.

“Gen. Mattis has put his finger on where the president has views that are very distinct from the vast majority of Republicans and probably Democrats, elected and unelected,” Toomey said Sunday in an exclusive interview on NBC’s “Meet the Press.”

Mattis announced his resignation Thursday, one day after Trump announced that the U.S. would be pulling all troops out Syria after declaring victory against ISIS. In his resignation letter, Mattis ran down a lengthy list of his values — the virtues of international “alliances and partnerships,” skepticism of Russia and China, and a commitment to an “international order.”

He then wrote that he was resigning because the president has “the right to have a Secretary of Defense whose views are better aligned with yours."

Toomey said that Trump should nominate a new defense chief who has a “traditional view about America’s role in the world” instead of someone with a more nationalist approach.

“I think the president does not share my view that the Pax-Americana of the post-war era has been enormously good for America,” Toomey added.

In addition to Trump’s announcement on Syria last week, defense officials told NBC News the administration is working on plans to withdraw troops in Afghanistan.

The departure of the decorated general sent a tremor through Washington, including through the ranks of the establishment Republicans in Congress who have long seen Mattis as a counter to Trump’s self-proclaimed nationalism, as well as Democrats who don’t trust the president on issues like foreign policy.

Illinois Democratic Sen. Dick Durbin, a member of Senate Democratic leadership, said in an exclusive interview on “Meet the Press” that he and other senators had privately pleaded with Mattis to stay in the administration.

“He obviously reached a breaking point,” Durbin said of Mattis.

“It breaks my heart that he’s going to step aside. We counted on him to be there and stop this president from his worst impulse."

Durbin went on to criticize the president’s Syria decision, raising concerns that the decision came after a phone call with Turkish President Recep Tayyip Erdogan, whose country sees the U.S.-allied Kurdish forces there as an enemy.

“Whether he's talking to [Russian President] Vladimir Putin or Erdogan, these autocrats have him enthralled. After a conversation, he'll make snap judgements and avoid the best advice that he could from people like General Mattis. That, to me, is the height of irresponsibility,” Durbin said.

"There are thousands of Kurds risking their lives to defeat ISIS who are now in jeopardy because of this impulsive decision.”

Trump and his allies see the Syria withdrawal as the president following through on his “America First” approach to both foreign and domestic issues, removing America from a Middle Eastern quagmire and letting regional forces carry the load.

Defending himself on Twitter Thursday, Trump asked rhetorically if America wants to be the “Policeman of the Middle East, getting NOTHING but spending precious lives and trillions of dollars protecting others who, in almost all cases, do not appreciate what we are doing?”

Does the USA want to be the Policeman of the Middle East, getting NOTHING but spending precious lives and trillions of dollars protecting others who, in almost all cases, do not appreciate what we are doing? Do we want to be there forever? Time for others to finally fight..... — Donald J. Trump (@realDonaldTrump) December 20, 2018

“Do we want to be there forever? Time for others to finally fight,” he wrote.

Mattis’s departure means that Trump will have a big decision ahead of him to find a new defense chief. Toomey said that while he’s typically given presidents of both parties a wide berth in choosing their own council, he said that “this one’s going to be tough.”

“I think this is so important, and the president’s views are so divergent, certainly from mine,” he said.