Barack Obama trolled Donald Trump as he read out mean tweets on Jimmy Kimmel Live.

The US president raised laughs as he read out a series of insults about himself - but it ended with a tweet from Trump himself.

"President Obama will do down as perhaps the worst president in the history of the United States!"

"At least I will go down as a president," Obama retorted before casually throwing the mean tweet phone on the floor.

Host Kimmel joked Obama had to "take time away from helping rig the election" to appear on the show - a dig at Trump who has repeatedly said the November 8 vote is rigged against him.

Kimmel asked Obama: "Do you ever laugh?" when watching Trumpon television. "Most of the time," Obama replied.

Obama's second and final term ends on January 20 as under the US constitution presidents are limited to two terms.

"If I were able to run for a third term, Michelle would divorce me," he said.