U.S. President Donald Trump reiterated on Monday (local time) that NATO has not supported the U.S. when the alliance most desperately needed it, following a meeting at the White House with NATO Secretary General Mark Rutter.

The meeting came after the President threatened to withdraw from the alliance on Tuesday, citing a lack of support from member states for a conflict between the United States and Israel, which has been temporarily suspended by a ceasefire agreement.

"NATO was not there for us when we needed it, and it won't be there for us when we need it again," Trump posted on Truth Social on Wednesday. "Remember Greenland, that big, poorly managed ice ball!"

Trump also wrote on Truth Social on Thursday morning: "Nobody understands anything unless there is pressure, including our very disappointing NATO!"

In an interview with CNN after Wednesday's meeting, Rutter stated that the two leaders had a "very frank and open, friendly" conversation, but did not specifically address whether Trump's threats to leave NATO were discussed.

Trump has been critical of NATO since his first term, pointing out that some member states have not adequately adhered to their defense spending commitments, but has maintained a good relationship with Rutter.

"He made it clear to me what he thinks about what has happened in the last few weeks," Rutter said, adding that it is "obvious" that Trump is "disappointed" with NATO.

He described the situation as "complex," emphasizing that NATO is at a turning point and that NATO member states respect Trump's leadership.

Rutter explained that NATO member states have reached a consensus on the need to degrade Iran's nuclear capabilities and reduce its missile range, which is why they all agree on Trump's attack on Iran.

He cited North Korea as an example, emphasizing that negotiations are not possible once a country has nuclear weapons, and thus defended Trump's "attack" as justified. These remarks came in response to a CNN anchor who pointed out that NATO is a "defensive" organization and Trump's operation in Iran was "offensive," and asked if NATO agreed.