The Iranian oil tanker at the centre of an international incident has been sailing just off the Syrian coast, satellite images appear to show.
The Adrian Darya-1 was seized by Gibraltar in July with the aid of British forces over fears it was bound for Syria, violating EU sanctions.
It was eventually released after assurances were given that it would not head for the war-ravaged country.
But images released on Saturday seemed to show it two nautical miles offshore.
The images, from US company Maxar Technologies, appeared to place the tanker very close to the Syrian port of Tartus on 6 September.
US National Security Advisor John Bolton tweeted that anyone who believed the ship was no longer headed for Syria was “in denial”.
“Tehran thinks it’s more important to fund the murderous Assad regime than provide for its own people,” he said, alongside another satellite picture. “We can talk, but #Iran’s not getting any sanctions relief until it stops lying and spreading terror!”
There is however no confirmation that the ship is unloading its cargo of 2.1 million barrels of Iranian crude oil.
Neither Iran nor Syria have commented.
In a statement, the UK’s Foreign Office called the reports “deeply troubling”.
A spokesperson said that if Iran had broken its assurances, it would be “a violation of international norms and a morally bankrupt course of action”.
The ship, originally known as Grace 1 when it was detained off the British territory in July, has caused a major diplomatic spat between Washington and Tehran.
British marines had helped Gibraltar authorities detain the vessel, partly drawing the UK into the row.
The United States made an official request to seize the ship in August, but the courts in Gibraltar denied it.
The US last year withdrew from the international 2015 deal to limit Iran’s nuclear programme, and reinstated sanctions. In response, Iran stopped abiding by some commitments in the deal.
The EU has sought to salvage the accord but the Iranian tanker was seized because it was suspected of heading to Syria, which would breach EU sanctions on that country.
The Gibraltar authorities freed the vessel on 15 August after receiving assurances from Iran that it would not discharge its cargo in Syria.
The US has been seeking to seize the tanker since it was released by Gibraltar. It issued a warrant and blacklisted the vessel, threatening sanctions on any country which offered it aid. The ship has since been sailing east across the Mediterranean.
Earlier this week it was revealed that a US official had even offered the captain of the ship millions of dollars to change course and sail the tanker to somewhere the US might be able to seize it.
A British-flagged tanker was seized by Iran in July, in what was widely seen as retaliation for Britain’s role in helping to seize the Iranian vessel – a link Tehran denies.
The Stena Impero was passing through the Strait of Hormuz when it was seized. It remains in the Iranian port of Bandar Abbas.