New Delhi, Oct. 25 -- US intelligence has found that Iran has "substantially increased" efforts to target American diplomats and government officials in the Middle East and other countries, with lethal plots against US citizens reaching "advanced stages", according to an October 23 memo obtained by Axios.

The warning, issued by Director of National Intelligence Jay Clayton to Secretary of State Marco Rubio, comes as the US State Department reduces personnel at several American diplomatic missions across the Middle East amid concerns about a wider regional conflict.

In the one-page, unclassified memo, Clayton reportedly offered to downgrade as much of the sensitive intelligence as possible to allow Rubio to share it more widely with Stat...