The majority of Americans believe Donald Trump’s summit with Kim Jong-un was a good idea, according to a new poll, sending the president’s approval rating to its highest point this year.

Days earlier it emerged that Mr Trump’s popularity among Republicans after 500 days in office is second only to that of George W Bush, whose standing benefited from the unifying effect of the 9/11 attacks.

With a Republican approval rating of 87 percent, Mr Trump was more popular within his own party than John Kennedy or Barack Obama, according to the latest polling by Gallup.

Analysts say that although the president remains a divisive figure within the country, his popularity within the Republican base has strengthened his grip on the party.

Washington insiders believe the numbers may dissuade a primary challenge ahead of the 2020 election and raise a growing prospect of a second Trump term.