Donald Trump's recklessness may lead to World War III: US Senator Bob Corker

A Republican Senator has warned that President Donald Trump was treating his office like "a reality show" with reckless threats toward other countries that could set the nation "on the path to World War III", the media reported.

Bob Corker, the Republican chairman of the Senate Foreign Relations Committee, on Sunday said he was alarmed about a President who acts "like he's doing 'The Apprentice' or something", reports The New York Times.

"He concerns me... He would have to concern anyone who cares about our nation."

The Senator's remarks came after Trump, earlier on Sunday, accused Corker of deciding not to run for re-election because he "didn't have the guts".

Trump said he had "begged" for his endorsement. "I said 'no' and he dropped out (said he could not win without my endorsement)."

He also said that Corker had asked to be Secretary of State. "I said 'no thanks'," he wrote.

In response, Corker shot back in his own tweet: "It's a shame the White House has become an adult day care centre. Someone obviously missed their shift this morning."

Trump poses such an acute risk, the Senator said, that "a coterie of senior administration officials must protect him from his own instincts".

"I know for a fact that every single day at the White House, it's a situation of trying to contain him."