US President Barack Obama on Tuesday called out Republican leaders on their continued support for their party's White House nominee Donald Trump, given some of the real estate mogul's incendiary statements.

"This isn't a situation where you have an episodic gaffe. This is daily and weekly where they are distancing themselves from statements he's making," Obama said of the party's top brass including House Speaker Paul Ryan and Senator John McCain.

"There has to be a point in which you say: 'This is not somebody I can support for president of the United States, even if he purports to be a member of my party.'"