The head of US national intelligence has warned of increasing threats to US officials abroad, saying Iran has stepped up efforts to target and kill them.

In a memorandum sent to US Secretary of State Marco Rubio, National Intelligence Director Jay Clayton, announced that the US has received information showing Iran has significantly intensified efforts to crack down on American personnel.

An American official confirmed the existence of a memorandum for journalists, under condition of anonymity, while its contents were reported earlier by Axios.

Iranian efforts to organise deadly attacks on American citizens have reached advanced stages, both in the Middle East and in some other countries, said the message to Rubio, broadcasting Telegraph.

According to the US official, the State Department is examining the level of personnel at American embassies, including the possibility that certain embassies and consulates will be transferred to the status of limited facilities. That would imply reducing the number of employees and the removal of family diplomats.

Early this week, the State Department ordered American employees who did not perform emergency tasks, as well as their families, to leave Saudi Arabia. The decision came after the escalation of attacks by Yemeni rebels, backed by Iran.

Since February, when the US and Israel started the war against Iran, the conflict has expanded, including Tehran’s revenge attacks on the Persian Gulf countries and Hezbollah attacks on Lebanon against Israel. About 50,000 American troops are deployed in the Middle East.

War has also affected global energy markets, increasing fuel prices. The conflict is widely unpopular among American voters, while discontent with the expensive costing of gasoline is putting President Donald Trump and his Republican allies under pressure ahead of the November 3rd Muslim elections.

Meanwhile, the US Army is preparing the possibility of sending thousands of additional maritime forces to the Middle East, at a time when Trump is considering relaunching the attacks.

According to officials who spoke on condition of anonymity for The Washington Post, the plans are intended to give the president and military commanders more flexibility through the delivery of up to three aircraft carriers and accompanying ships to the region during November.

In Friday’s memorandum, Clayton said he is demanding that as much intelligence information be declassified, so that Ruby shares it with State Department personnel. /Telegraphy/