Donald Trump has said that Iran “can frankly do whatever they want” in Syria, as he answered questions from reporters about the planned US withdrawal from the country.

His latest announcement has caused significant embarrassment to other high-level US officials, including National Security Advisor John Bolton, who had claimed that making sure Iranian forces left Syria was a top administration priority.

Mr Trump suddenly announced his intention a fortnight ago to pull American troops out of Syria, prompting James Mattis, the US Secretary of Defence, to resign.

With Mr Bolton in the room, Mr Trump told journalists on Wednesday: “I don’t want to be in Syria forever, it’s sand and death. We’re not talking about vast wealth.”

He blamed his predecessor for his own decision, saying Barack Obama “gave up Syria years ago when he didn’t violate [enforce] the red line”, a reference to the former president's warning that Syria using chemical weapons would be “crossing a red line”.

Mr Trump continued: “I did when I shot 59 missiles but that was a long time later. And when President Obama decided not to violate his statement — that never cross the red line — and then they did and he didn't do anything about it.”

He also claimed that “Iran is pulling people out of Syria”, a statement which one unnamed senior Israeli official responded to by saying he was “quite simply in shock.”

“Trump simply does not know what is happening in Syria and the Iranian entrenchment there,” the unnamed official told Israeli news site Ynet.

“It is sad that he is not attentive to intelligence materials.”

Last month, Israeli Prime Minister Benjamin Netanyahu said that Trump's decision “does not change our policy to stand firm against Iran in Syria.”

Commentators were quick to note how differently Mr Netanyahu, who was vocally critical of President Obama's attitude towards Iran, might have reacted had Mr Trump's predecessor said something similar. 

Earlier on Wednesday, Mr Netanyahu tweeted a picture of himself meeting Mike Pompeo, the US Secretary of State, while in Brazil for the inauguration of the country’s new leader, Jair Bolsonaro.

“I am very appreciative of the support that Secretary Pompeo and President Trump gave to Israel’s efforts at self-defence against Syria just in the last few days,” Mr Netanyahu wrote, just hours before Mr Trump’s latest comments.