US President Donald Trump on Tuesday named Gina Haspel as the first woman head of Central Intelligence Agency (CIA). Trump also replaced US Secretary of State Rex Tillerson with CIA director Mike Pompeo.

The resignation represents the biggest shakeup of the Trump Cabinet so far and had been expected since last October when reports surfaced about a falling out between Trump and Tillerson, 65, who left his position as chief executive of Exxon Mobil to join the administration.

US stock index futures pared their gains and the dollar also trimmed gains versus the yen while extending losses versus the euro amid the news.

Trump publicly undercut Tillerson's diplomatic initiatives numerous times, including on Monday when the former secretary of state's comments about Russia appeared to be at odds with those of the White House.

Tillerson also appeared out of the loop last week when Trump announced he would meet with North Korea's leader and become the first sitting US president to do so.

"Mike Pompeo, Director of the CIA, will become our new Secretary of State. He will do a fantastic job! Thank you to Rex Tillerson for his service! Gina Haspel will become the new Director of the CIA, and the first woman so chosen. Congratulations to all!" Trump said on Twitter.

ALSO READ | I'm a genius! Twitter has a field day after Trump tweets saying he is mentally stable

ALSO READ | Sean Spicer resigns as Donald Trump's White House press secretary