Prime Minister Theresa May is not afraid to tell Trump when he says something wrong, she insisted on Sunday.
The two world leaders are due to meet in Washington on Friday, making the UK Prime Minister the first world leader to meet him since he was sworn in as President.
In an interview with the BBC she said she would use to opportunity to discuss a US-UK trade deal as well as NATO and defeating terror.
May, who is Britain's second female premier, made the comments after thousands of women marched in London on Saturday to protest about Trump's attitude to women, joining demonstrations held from Australia and Asia to continental Europe and Washington.
"I've already said that some of the comments that Donald Trump has made in relation to women are unacceptable, some of those he himself has apologised for," May told the BBC.
"When I sit down (with Trump) I think the biggest statement that will be made about the role of women is the fact that I will be there as a female prime minister ... Whenever there is something that I find unacceptable I won't be afraid to say that to Donald Trump."
The meeting on Friday will be an opportunity for May, who initially struggled to build relations with Trump's team, to discuss what has long been called the "special relationship" between London and Washington, a pillar of British foreign policy.
But the visit will also be clouded by his perceived attitude towards women, including a boast in a 2005 video about grabbing women's genitals, which prompted the wave of mass protests on Saturday.
