A fragile ceasefire between Iran and Israel appeared to hold Tuesday after initially faltering, and U.S. President Donald Trump expressed frustration with both sides, saying they had fought ''for so long and so hard'' that they do not know what they are doing.

The head of the Israel Defense Forces said Tuesday that “the campaign against Iran is not over” as a ceasefire between the two countries went into effect. President Donald Trump also vowed that Israel will not attack Iran and told Israel to bring its pilots home.

The US president is due to arrive at the Nato summit shortly after earlier accusing Israel and Iran of violating the truce.