"I complained about that a long time ago, and they made a change - and now they do fight terrorism," Trump said. "I said it was obsolete. It's no longer obsolete."
It's unclear what changes the president was referencing. Nato did add a new assistant secretary general position focused on intelligence and security in July 2016, although experts say the change does not mark a major shift for the organisation and point out that Nato has long addressed concerns of terrorism. For months after the position was created, Trump continued to call Nato obsolete.
Stoltenberg told the President he was "right," but described the change in far different terms.
"We have established a new division for intelligence, which enhances our ability to fight terrorism, and working together in the alliance to fight terrorism even an even more effective way," Stoltenberg said. "But we agreed today, you and I, that Nato can and must do more in the global fight against terrorism."
In brief remarks, Trump again called on Nato members to "meet their financial obligations and pay what they owe," noting that member-nations are expected to contribute 2 per cent of their GDP to defence. Stoltenberg confirmed that ensuring the cost burden is better shared among countries has become a top priority for him.
Later, Trump said he asked Stoltenberg to look into collecting back-dues from countries, something that Stoltenberg did not verbally agree to do. Trump has consistently misrepresented the financial obligations of Nato members, saying they "owe vast sums" in dues and the situation is unfair to the United States. Nato members do not owe dues or back payments.
Trump also thanked Nato members for condemning Syrian President Bashar al-Assad's use of chemical weapons and "the barbaric killing of small and helpless children and babies". At one point, Trump referred to the Syrian leader as a "butcher".
Trump backed away from several other firm positions that he had held for months on the campaign trail.
Early in the day, the Government ended a federal government hiring freeze that Trump had promised to institute, although departments have been told to find other ways to shrink staff sizes.
Then, in an interview with the Wall Street Journal, the President announced he no longer considers China a currency manipulator, he now supports lower interest rates and the US Export-Import Bank, and he would consider renominating Federal Reserve Chairwoman Janet Yellen when her tenure is up next year, despite saying on the campaign trail he would "most likely" not reappoint her.
Last week, Trump abandoned his longtime stance that the United States should not get involved with Syria when he approved a strike on an airbase there.
"I felt we had to do something about it," Trump said of the Syria bombing. "I have absolutely no doubt we did the right thing. And it was very, very successfully done, as you well know."