"In fact, Iran has only behaved worse since the deal was approved. Iran destabilises this entire region."
Saudi Foreign Minister Adel al-Jubeir said the kingdom "supports the policy of the Trump Administration against Iran and to improve the terms of the nuclear agreement with Iran."
Downing Street announced that British Prime Minister Theresa May has had separate discussions with President Emmanuel Macron of France and Chancellor Angela Merkel of Germany in which they solidified their stance in support of the deal.
In a nod to Trump and in the wake of visits to the US last week from Macron and Merkel, the three leaders acknowledged there were key issues that needed to be addressed, including the question of Iran's ballistic missile programme and what happens when the deal expires.
A Downing Street spokesman said: "They discussed the importance of the Iran nuclear deal as the best way of neutralising the threat of a nuclear-armed Iran, agreeing that our priority as an international community remained preventing Iran from developing a nuclear weapon. They agreed that there were important elements that the deal does not cover, but which we need to address.
"Acknowledging the importance of retaining the deal, they committed to continue working closely together and with the US on how to tackle the range of challenges that Iran poses."
Iran has threatened to restart nuclear activity should Trump scupper the agreement, with President Hassan Rouhani calling Trump a "tradesman" who lacks the qualifications to deal with a complex international pact.
Rouhani told Macron in a telephone conversation that the Iran nuclear deal was "not negotiable".
Pompeo's tough line was welcomed by his hosts, particularly in Israel, which considers Iran its greatest threat and has led calls for the West to revise or reject the 2015 nuclear deal with Iran.
"We remain deeply concerned about Iran's dangerous escalation of threats to Israel and the region and Iran's ambition to dominate the Middle East remains," Pompeo said after a nearly two-hour meeting with Israeli Prime Minister Benjamin Netanyahu.
"The United States is with Israel in this fight."
Israel has cited Iran's hostile rhetoric, support for anti-Israel militant groups and development of long-range missiles. It also has complained the nuclear deal does not do enough to prevent Iran from developing a nuclear-weapons capability, and expressed concerns about Iran's involvement in the civil war in neighbouring Syria.
Israel says it will not allow Iran to establish a permanent military presence in Syria, fearing the Iranians will use it to launch attacks.
"Iran must be stopped, its quest for a nuclear bomb must be stopped, its aggression must be stopped and we're committed to stopping it together," Netanyahu said.
Speaking on Fox News, John Bolton, the US national security adviser, said Trump had yet to make a decision.
- additional reporting AP
