Trump fires national political director

US Republican presidential candidate Donald Trump has fired his national political director after six weeks on the job, campaign sources say.

Trump told staffers and supporters gathered backstage before a campaign rally in California on Wednesday that political director Rick Wiley "should be fired" for his handling of a fundraising deal with the Republican National Committee, according to the sources.

The RNC fundraising agreement included 11 states but not Nevada, where Republicans in the state are angling for key victories in the November elections.

Three sources confirmed Trump said Wiley should be fired after Nevada Republican Party chairman Michael McDonald told Trump that Wiley was responsible for leaving Nevada out of the deal.

McDonald did not return calls seeking comment. Wiley did not respond to emails, text messages and phone calls seeking comment.

The move is the latest in a tug of war between Trump's original campaign team, including press secretary Hope Hicks and campaign manager Corey Lewandowski, and a group of professionals he brought in later to shore up support from more traditional corners of the Republican Party.

The new arrivals, led by veteran strategist Paul Manafort, whom Trump hired in late March, have urged Trump to tone down some of his most provocative positions, such as his proposed ban on Muslims entering the US.

But Trump reprimanded Manafort, according to two sources familiar with the conversation, after Manafort told a gathering of RNC members at an April meeting in Florida that Trump was only "acting" when describing his proposed Muslim ban or his plan to build a wall along the US-Mexico border.

Manafort hired Wiley on April 13.

A statement issued by the Trump campaign said Wiley had been hired on a "short-term basis as a consultant until the campaign was running full steam" and it thanked him for "for helping us during this transition period".

Manafort did not responds to calls and emails seeking comment.