Since last year's North Atlantic Treaty Organisation summit allies had added $US41bn to their budgets, he said, and now they would redouble their efforts.
The U.S. president's shake-up of the NATO summit had begun Wednesday at a working breakfast with NATO Secretary General Jens Stoltenberg, when Trump accused Germany of being controlled by Russian interests.
Canada did agree to the two per cent benchmark in Wales, but the Trudeau government's spending projections show plans to reach only 1.4 per cent of GDP by 2024.
"Georgia has a lot of allies who are interested in Georgia and actively support the agenda of our country", said Georgian President Giorgi Margvelashvili.
While not commenting on the 4% figure, Mr Hunt supported Mr Trump's assertion that other North Atlantic Treaty Organisation members needed to to play a greater role.
President Trump has arrived in the United Kingdom for a much-anticipated visit that is expected to draw large protests.
"We consider Trump a negotiating partner", Kremlin adviser Yuri Ushakov told reporters in a briefing on Monday's summit in Finland.
Member nations agree to specific targets for military spending, though the dollar amounts - and total percentage of North Atlantic Treaty Organisation budget - vary depending on their size.
And while the president has said he ultimately wants to up commitments doubled to 4 percent, for now he said that countries have agreed to move at a "faster clip" to meet the 2 percent threshold.
Merkel, who grew up in communist East Germany, shot back that she had "experienced myself a part of Germany controlled by the Soviet Union, and I'm very happy today that we are united in freedom as the Federal Republic of Germany and can thus say that we can determine our own policies and make our own decisions and that's very good".
Trump said he does not anticipate a "Perry Mason" moment when he confronts Putin on the issue, a reference to a decades-old US television courtroom drama, and he predicted Putin would continue to deny the allegations.
"President Trump created for the second day a crisis on [NATO] spending".
Negotiations would then be widened to include members of both delegations, he said, adding that Russian Foreign Minister Sergei Lavrov will hold parallel talks in Helsinki with his US counterpart, Mike Pompeo.
At the summit working dinner on Wednesday, Theresa May warned Mr Trump not to ignore the "malign behaviour" of Russian Federation when he meets President Vladimir Putin in Helsinki. "There won't be a Perry Mason here, I don't think, but you never know what happens, right?"
Trump reiterated Friday that he is not going into the meeting with high expectations, but he said the two leaders would also discuss "a number of things", including cuts to nuclear weapons arsenals. She wanted to go a different route.