US vice president Mike Pence is set to visit the UK and Ireland on behalf of Donald Trump.
The Republican will be in the UK to discuss Brexit, Iran and the "threat of Chinese malign influence" between 4 and 5 September, the White House said.
He will then travel to Ireland on 6 September to meet Taoiseach Leo Varadkar.
There, according to the White House, he will voice the States' "commitment to maintaining peace, prosperity, and stability in Ireland by upholding the Good Friday Agreement".
He will also discuss trade, investment and strengthening the economic relationship between the two nations.
The announcement of the visit came after US House speaker Nancy Pelosi warned there is "no chance" of a US-UK trade deal if Brexit jeopardises the peace accord in Northern Ireland.
She said the Democrats, who control the House of Representatives, will block the deal in Congress if the EU departure "undermines" the agreement.
Mr Trump was met by protests during his two visits to the UK as president.
Mr Pence is a controversial figure and has been particularly criticised over his stance on LGBTQ rights.
Chad Griffin, president of the Human Rights Campaign, one of the US's largest gay rights groups, once said Mr Pence "poses one of the greatest threats to equality in the history of our movement".