After raising the threat of the USA leaving NATO, Trump said on Thursday that there are no problems, adding that America's allies had pledged to increase defense spending commitments "very substantially".
Donald Trump told a press conference that the United States were not treated fairly but now they are.
Trump has described the spending situation as "disproportionate and not fair to the taxpayers of the United States".
President Donald Trump "upended world order" and could "turn back the global clock centuries" said Fox News anchor Shepard Smith in a blistering 10-minute opening to his show on Wednesday regarding the President's multiple anti-NATO tirades.
After the emergency session, Trump said that the alliance is "very unified, very strong, no problem".
"Dear America, appreciate your allies, after all you don't have that many", Tusk said, before reminding Trump that European troops had come to America's aid following the September 11, 2001 attacks on the United States.
During a working breakfast that marked the start of the summit, Trump claimed Germany is "controlled" by Russian Federation due to an energy partnership between the two countries.
The Nato leaders, gathered in Brussels, held an unplanned emergency meeting earlier on Thursday after Mr Trump told allies to immediately increase their defence spending, diplomatic sources said. Trump's suggestion was informal and made in a closed-door session of on Wednesday, but it did little to ease tensions at an already charged meeting.
"That's why we are pleased that based on the consultation we did with Canadians and our own defence policy review, we're moving forward with increasing by 70 per cent our defence investments over the coming decade". "And I really believe that when he tells me that, he means it".
Chris Wallace announced Thursday that he will interview Russian President Vladimir Putin after Monday's summit with President Donald Trump in Helsinki, Finland.
Trump had spent his time in Brussels berating members of the military alliance for failing to spend enough of their money on defense, accusing Europe of freeloading off the USA and raising doubts about whether he would come to members' defense if they were attacked. "You'll be the first to know".
Instead, a series of events - a black-tie dinner with business leaders, a meeting with May and an audience with Queen Elizabeth II - will happen outside the bustling city, where Mayor Sadiq Khan has been in a verbal battle with Trump.
"The United States' commitment to North Atlantic Treaty Organisation remains very strong", Trump told reporters at a surprise news conference following an emergency session of North Atlantic Treaty Organisation members held to address his threats.
NATO Secretary General Jens Stoltenberg tried to keep the peace. US Turkish relations have recently been strained because of issues ranging from Syria to Iran, but some diplomats say the two leaders - both criticised for their polarising politics - have established a bond.
Not only did Trump demand on Twitter on Thursday that countries meet the 2% level by this year, not 2024, but he also said all countries should eventually hit 4%, which is more than even the USA now spends.