US President Donald Trump, annoyed by the reluctance of NATO allies to help secure the Strait of Hormuz and angry that his plans to buy Greenland have not come to fruition, discussed with his advisers the possibility of withdrawing US forces from Europe, a senior White House official told Reuters.

No decision has been made and the White House has not asked the Pentagon to draw up specific plans to reduce the number of U.S. troops in Europe, said this official, who asked not to be named.

However, the mere fact that there has been any discussion of the issue underscores how much Washington’s relations with its European NATO allies have deteriorated in recent months. It also suggests that the visit of Mark Rutte, the alliance’s secretary-general, to the White House on Wednesday did nothing to improve relations, which are arguably at their worst level since NATO’s founding in 1949.

There are more than 80,000 US troops stationed in Europe today – more than 30,000 in Germany. Several thousand are also in Italy, Britain and Spain.

NATO did not immediately respond to a request for comment.

The official did not specify which countries would be affected or how many troops might be withdrawn if Trump decides to go ahead with the plan.

Alliance in crisis

Although Trump’s relationship with NATO has always been volatile – for years he has accused the Europeans of not spending enough on their defense – the past three months have been particularly tumultuous. In January, the US president sparked a transatlantic crisis when he repeated his threat to annex Greenland, which is the territory of Denmark, a US NATO ally. After war broke out in Iran on February 28, he expressed resentment that his allies had not offered to help reopen the Strait of Hormuz.

Diplomatic officials at NATO say the US did not make clear whether it expected to launch a mission to Hormuz during or after the war. They also did not specify what they would expect from each NATO country separately.

The Wall Street Journal reported Wednesday that U.S. government officials are discussing the possibility of moving troops stationed in Europe from countries whose leaders have criticized the U.S.-Israel war on Iran to other European countries whose leaders have appeared more supportive.

The White House official told Reuters that Trump was specifically discussing returning the soldiers back to the US, rather than moving them to different, foreign countries.