Tehran, meanwhile, has threatened attacks in the Strait of Hormuz if diplomacy with the US fails.

Trump also claims that secret backchannel talks are taking place between the US and Iran. 

However, Iran’s Islamic Revolutionary Guard Corps, or IRGC, has rejected the claim, saying there are no secret talks with Washington. 

Amid the ongoing conflict and rising threats from both sides, the United Nations has again urged the two countries to return to talks. 

UN spokesman Stephane Dujarric says there is no military solution to the conflict and calls for a peaceful and lasting settlement through dialogue.