Reporter to David Cameron: What would you advise American voters to do about Donald Trump?

British Prime Minister David Cameron handled delicately a question about Donald Trump at a joint press conference with US President Barack Obama on Friday.

During a press conference in London following a meeting between Cameron and Obama, a Bloomberg reporter asked what Cameron would advise American voters to do about Trump, the frontrunner for the Republican nomination for president.

"As a friend, and speaking honestly, what would you advise American voters to do about Donald Trump?" Bloomberg White House correspondent Justin Sink asked.

Obama interjected as people in the room laughed.

"That was so predictable!" he said.

Cameron eventually dodged the question.

"As for the American elections, I've made some comments in recent weeks and months, I don't think now is the moment to add to them or subtract from them," Cameron said.

"But I think just as a prime minister who's been through two general elections leading my party, you always look on at the US election in awe at the scale of the process and the length of the process. And I marvel at anyone who's left standing at the end of it," he added.

Obama quipped that "fortunately, we're term limited."

"So I, too, can look in awe at the process," he said.

Cameron has previously spoken out about Trump, saying that a Trump visit to the UK would unite British people against him.