According to Bolton, the tankers which witnessed explosions two weeks ago off the coast of Fujairah, UAE were damaged by "naval mines almost certainly from Iran".

Previously, US Secretary of State Mike Pompeo brought the same charges, claiming that Tehran might be behind the incident. The Islamic Republic, however, repeatedly denied the allegations, stressing that the attacks must be investigated in order to preserve stability in the region.

The news comes as Washington has stepped up the US military presence near Iran's borders, deploying an aircraft carrier strike group, Patriot missiles, B-52 bombers and F-15 fighters to the Middle East. 

Addressing the move, Bolton has called it a "clear and unmistakable message" to Tehran amid the partial suspension of the nuclear deal by Iranian authorities.