Donald Trump 'furious' over Andy Burnham's cabinet pick: Here's why

United States (U.S.) President Donald Trump is reportedly angry with British Prime Minister Andy Burnham after the latter appointed Ed Miliband as the UK’s new foreign secretary.

The White House insiders have warned that the new appointment of Miliband who repeatedly criticised the US president could strain relations between the two allies.

According to The Independent, people close to the White House believe Trump has not forgotten Miliband's years of criticism directed at him. 

One source claimed the U.S. president "will not forget" the comments despite Burnham's efforts to reset relations with Washington.

Miliband has repeatedly criticised Trump over the years, describing him as a threat to democracy and opposing several of his policies. He often lashed out at the Republican party leader over his stance on climate change and international cooperation.

The new UK foreign minister once described the 80-year-old US president as “a racist, misogynistic, self-confessed groper.”

As foreign secretary, he will now become Britain's top diplomat and one of the key figures responsible for dealing directly with the Trump administration.

The reported frustration comes just days after Burnham spoke with Trump following his appointment as prime minister. 

Both sides publicly described the conversation as positive, raising hopes that the two governments could maintain close ties despite their political differences.

Despite concerns inside Washington, British officials insist the "special relationship" between the UK and the US remains a priority.

Miliband is also expected to work closely with US Secretary of State Marco Rubio on issues ranging from Ukraine and the Middle East to trade and climate policy.