Republican senator Bob Corker has warned that Donald Trump risks setting the United States “on the path to world war three” as the pair continued to exchange public barbs.

The US president had blamed his former political ally for the Iran nuclear deal in a series of derisive Twitter posts that drew a sharp riposte from Corker, who chairs the important Senate foreign relations committee.



Corker told the New York Times he was alarmed about a president who acts “like he’s doing The Apprentice or something” – in a reference to the reality television show that Trump had once hosted.

“He concerns me. He would have to concern anyone who cares about our nation,” the senator, who announced his retirement last month, said.

Corker dismissed the idea that Trump may be using provocative comments about North Korea to advance US negotiations being conducted by secretary of state Rex Tillerson by playing “bad cop” to the top diplomat’s “good cop” effort to broker a deal with Pyongyang.

“He’s hurt us as it relates to negotiations that were under way by tweeting things out,” Corker told the paper. “A lot of people think that there is some kind of ‘good cop, bad cop’ act under way, but that’s just not true.”

Corker said most Senate Republicans shared his views about the president.

“Look, except for a few people, the vast majority of our caucus understands what we’re dealing with here ... They understand the volatility that we’re dealing with and the tremendous amount of work that it takes by people around him to keep him in the middle of the road.”



Corker had been a national security adviser to Trump during the 2016 presidential campaign and on Trump’s shortlist last year for both vice-president and secretary of state.

But the relationship between the two men has greatly deteriorated.

More recently, Corker has criticised Trump, taking issue with the president’s response to a white supremacist demonstration in Charlottesville in August. Critics assailed Trump for saying rival protesters were also to blame for violence.



On Sunday, Trump tweeted that Corker had “begged him” for his endorsement in Tennessee but “I said ‘NO’ and he dropped out (said he could not win without my endorsement),” Trump wrote.

Senator Bob Corker "begged" me to endorse him for re-election in Tennessee. I said "NO" and he dropped out (said he could not win without... — Donald J. Trump (@realDonaldTrump) October 8, 2017

An hour later Corker tweeted back: “It’s a shame the White House has become an adult day care center. Someone obviously missed their shift this morning.”

Referring to the Twitter spat, Corker told the New York Times: “I don’t know why the president tweets out things that are not true. You know he does it, everyone knows he does it, but he does.”

Corker’s chief of staff, Todd Womack, said Trump called the senator last Monday, asked him to reconsider his decision not to seek re-election in 2018, “and reaffirmed that he would have endorsed him, as he has said many times”.



Trump’s dispute with Corker could also have implications for the president’s policy goals of repealing Obamacare and passing tax reform. Republicans control both houses of the US Congress but hold only a narrow majority, 52-48, in the Senate, which means Trump has only a slim margin for potential defections from within his own party on legislation.

Even before Trump’s Twitter attacks on Corker, the senator has said he would have difficulty supporting any tax package that added to the federal deficit, posing a potential hurdle for the president’s tax plan.

On Iran, Trump is expected to disclose within days a plan to decertify the 2015 international nuclear agreement with Tehran, putting the agreement’s future in the hands of Congress, where Corker would play a central role in determining its fate.



Trump has long criticised the pact, a signature foreign policy achievement of Barack Obama in which Iran agreed to reduce its nuclear program in exchange for easing of international sanctions.