US President Donald Trump said on Friday that his country will send additional 1,500 troops to the Middle East amid escalating tension with Iran.

Trump told reporters at the White House that the extra deployment, which is "relatively small number of troops," is mainly a protective measure.

US media reported earlier in the day that the White House had notified Congress about Trump's decision.

Washington and Tehran have been locked in a war of words over the past two weeks amid escalating tension that had been stoked up following America's military buildup in the Middle East.

Iran has vowed to withstand the US "bullying policies."