US President Donald Trump has taken to Twitter to directly threaten Iran, raising concerns about a potential conflict between the two countries.
United States President Donald Trump. Photo: AFP
He said: "If Iran wants to fight, that will be the official end of Iran. Never threaten the United States again."
The Trump administration has accused Iran of threatening US troops and interests.
Tehran has described US moves as "psychological warfare" and a "political game."
In recent months Mr Trump has tightened economic sanctions against Iran, and his administration has built up the US military presence in the region, sending warships and warplanes to the Gulf earlier this month.
The US state department has ordered the departure of "non-emergency employees" from Iraq.
The US military said last week the threat level in the Middle East had been raised in response to intelligence about Iran-backed forces in the region.
It contradicted a British general who had said there was "no increased threat".
Last week it was reported that US investigators believe Iran or groups it supports used explosives to damage four tankers off the coast of the United Arab Emirates. Large holes were found in the hulls of the tankers, but no evidence has been released showing a link to Iran.
However, US Secretary of State Mike Pompeo has downplayed the rising tensions, saying the US does not seek war with Iran - a sentiment echoed by Iran Supreme Leader Ayatollah Ali Khamenei who said his country does not want war with the US.
Last year, Mr Trump unilaterally withdrew from a landmark nuclear deal the US and other nations had agreed with Iran in 2015.
- Reuters / BBC / RNZ