US President Donald Trump has resumed his journey to Switzerland to attend the World Economic Forum in Davos after what the White House described as a minor technical issue forced Air Force One back to Washington.
Mr Trump was due to give an eagerly awaited address to delegates this afternoon.
His visit has been overshadowed by a crisis in transatlantic relations prompted by his persistent claims that the United States must acquire Greenland.
Taoiseach Micheál Martin will also arrive at the meeting later this evening for a number of engagements.
Reporters on Air Force One noticed that the lights went out in the cabin shortly after take off from Andrews airbase outside Washington. The Boeing 747 turned around and the entourage was transferred to a smaller 757, which took off around 5am Irish time.
In all the delay lasted two hours, an inauspicious start to what is expected to be one of the most consequential visits to the World Economic Forum by a US president.
Asked at a White House news conference last night how far he was prepared to go to seize Greenland, Mr Trump replied, "You'll find out".
Watch: Donald Trump says 'you'll find out' when asked how far he would go to seize Greenland
Questioned if collapsing the NATO alliance was a price worth paying to acquire the island, Mr Trump said no-one had done more for NATO than he had.
EU leaders have pushed back angrily against Mr Trump’s threat to impose tariffs on those countries who have opposed his seizure of Greenland, with French President Emmanuel Macron essentially describing him as a bully during yesterday's Davos session.
Watch: Emmanuel Macron says France prefers respect over bullies
Mr Trump has responded to European anger with a volley of insults and mockery, posting a doctored image of him and administration figures planting a US flag on Greenland.
The Financial Times has reported that the launch of a planned $800 billion economic package for Ukraine, to be agreed by Europe, Kyiv and the US in Davos has been derailed by the Greenland crisis.
Mr He has not ruled out the use of the US military to take over Greenland, which has a US military base.
NATO leaders have warned that Mr Trump's Greenland strategy could upend the alliance. Mr Trump has linked Greenland to his anger at not receiving a Nobel Peace Prize.
In a breach of diplomatic protocol, the US president released the text of a private message he received from French President Emmanuel Macron in which Mr Macron urged Mr Trump to join him and other G7 leaders in Paris after Davos, an idea Mr Trump dismissed.
"I do not understand what you are doing on Greenland," wrote Mr Macron.
Leaders of Denmark and Greenland have offered a wide array of ways for a greater US presence on the strategic island but this has not placated Mr Trump.
Mr Trump's original purpose for going to Davos was to talk up the strength of the US economy.
He is giving a keynote address that he said he would use to discuss economic successes at home, despite opinion polls showing Americans are broadly unhappy with his handling of the economy. The White House said he would address the rising cost of housing with a plan to let Americans use money in their 401(k) retirement savings plans for down payments on homes.
During his stay, Mr Trump plans to have separate meetings with the leaders of Switzerland, Poland and Egypt, the White House said.
Tomorrow, he is due to preside over a ceremony celebrating the 'Board of Peace', a group he formed that is aimed at redeveloping Gaza amid a fragile ceasefire between Israel and Hamas.
Mr Trump has drawn some worries by saying the board may work on global crises beyond Gaza, a role traditionally performed by the United Nations.
He told a news conference yesterday he likes the United Nations but it has "never lived up to its potential".
Additional reporting Reuters
