U.S. President Donald Trump's communications director is leaving the job, the White House said on Tuesday, as the president considers wider staff changes to try to contain political damage from investigations into Russia and his presidential campaign.

Mike Dubke confirmed reports he had resigned, saying in a statement, "It has been my great honor to serve President Trump and this administration." Dubke, who had been in the job just three months, gave no reason for leaving.

Trump, who returned to Washington on Saturday after a nine-day trip to the Middle East and Europe, has been expected to shake up staff to tackle the firestorm over investigations into alleged Russian meddling in the 2016 presidential election and communication between Russia and Trump's campaign and transition team.

Trump plans to bring in new aides to the White House, adding experienced political professionals including a former campaign manager, according to administration officials and people close to the president.

Dubke, who was joined the White House in March to head the office that runs press and other public relations issues, oversees the White House's message strategy while spokesman Sean Spicer, a more high-profile figure, handles daily media briefings.

The Republican president came home to face more questions on Russia after media reports about communications during and after the campaign between his son-in-law and close adviser, Jared Kushner, and Russia's ambassador to Washington.

Spicer was asked on Tuesday whether Trump knew about reported efforts by Kushner in December to set up a back channel for communications with Russia.

"What your question assumes is a lot of facts that are not substantiated by anything but anonymous sources that are so far being leaked out," he told a news briefing.