Donald Trump wrong-footed the British government and unionist politicians with his prediction that a united Ireland will happen and his declaration that he would "love to see it".
Unionist politicians in Northern Ireland have been ardent supporters of the US president.
In fact, back in September 2020, three DUP MPs - Ian Paisley Junior, Sammy Wilson and Paul Girvan - posed outside the Houses of Parliament in Westminster holding a flag proclaiming support for Mr Trump's election campaign, including the phrase "Make America Great Again".
Senior members of the DUP and the Ulster Unionist Party have frequently endorsed President Trump’s policies on a wide range of issues, including his support for Israel.
But his 'Make Ireland One Again' sentiments have sent them into a tailspin.
Hitherto keen to praise Mr Trump’s uncompromising stance on a range of issues, they have been quick to denounce him as fickle and uninformed.
Sinn Féin on the other hand has been strongly critical of the man in the White House on a wide range of issues and yet now the party has what it will no doubt be tempted to sell as an endorsement of its campaign for a border poll.
The British government was also surprised and no doubt dismayed with his comments, which have come just weeks after UK Prime Minister Andy Burnham said discussions about a border poll were "off the table".
The Government under Taoiseach Micheál Martin has advocated a cautious approach to the border poll issue, taking the view that the time is not right.
While it may welcome the sentiments, the timing may also have caused it some unease.
It is of course impossible to say precisely why President Trump said what he did.
The fact that he doubled down on the sentiments today, stating that Irish unity "seems to be one of the naturals of all time", suggests it was not simply a slip of the tongue.
The remarks may well be aimed at his Irish-American audience back home as the Republican Party seems destined to take a battering in the Congressional midterm elections in November.
The comments do not signal a change of US foreign policy and a border poll is no closer now that it was before President Trump made his unexpected remarks.
But they will certainly add fuel to the fire, as he has done on many other issues.
Read more:
In pictures: Donald Trump's visit to Ireland
