What would a US claim over the Strait of Hormuz mean?

President Donald Trump said on 14 August that the United States would designate the Strait of Hormuz as US territory "pretty soon", a move that would represent a dramatic escalation in the months-long conflict between Washington and Tehran.

Trump, speaking at a police academy in New York, suggested that a US naval blockade of the waterway meant the United States effectively already controlled it, says Al Jazeera.

The remarks have been dismissed by Iranian officials and legal experts, who say the United States cannot simply annex the strategic waterway. Any attempt to assert sovereignty over the strait would also have major implications for international law and global energy supplies.

Here is what is known about the Strait of Hormuz and Trump's proposal.

Why is the Strait of Hormuz important?

The Strait of Hormuz is a narrow waterway between Iran and Oman that connects the Persian Gulf with the Gulf of Oman and the Arabian Sea.

It is one of the world's most important energy chokepoints, carrying about one-fifth of global oil and gas supplies. Disruption to shipping through the strait can therefore affect energy prices and global trade far beyond the Middle East.

Iran and Oman are the two countries with coastlines on the strait.

What is happening in the strait?

The remarks come as the United States and Iran remain locked in a conflict that began on 28 February.

Iran has blocked passage through the waterway, seeking to use control over the strait as leverage in the conflict, while the United States has imposed a naval blockade on Iranian ports.

The confrontation has also become an economic issue for Washington. Petrol prices have risen above $4 a gallon, while the war has faced weak public support in the United States, with approval at about 35%.

The administration is also under pressure over reported shortages of some munitions as the conflict continues, with the November midterm elections approaching.

Trump has repeatedly threatened further military action against Iran before pulling back, at times comparing the negotiations to a game of "chess".

What has Iran said?

Iranian officials have rejected Trump's proposal.

Deputy Foreign Minister Kazem Gharibabadi described the US claims as "nonsense" and "fanciful delusions", saying the strait could not be seized by "tweet" or "aircraft carrier" and remained under Iranian command.

Iran is also negotiating with Oman, the only other country bordering the strait, over the management of maritime traffic.

Tehran is now demanding the removal of the US blockade and sanctions as conditions for reopening the waterway, concessions it had previously sought as part of negotiations to end the war.

Could the United States legally annex the strait?

Legal experts say a unilateral declaration by the US president would not be sufficient to annex territory.

Bruce Fein, a former associate deputy attorney general, said a president does not have the constitutional authority to annex territory on his own. Such a move would require congressional action or a treaty ratified by the Senate.

International law presents another obstacle.

Under the UN Convention on the Law of the Sea, the waters of the strait lie between the territorial seas of Iran and Oman. The convention provides rules governing navigation through international straits and does not give a foreign state the right to unilaterally claim sovereignty over such waters.

Experts have argued that an attempt to seize the strait by force could also violate the UN Charter's prohibition on the use of force and amount to what has been described as a "crime of aggressive war".

Could the United States control the strait militarily?

Legal specialist Natalie Klein said the most plausible legal basis for asserting direct control would be through the powers of an occupying force.

That, however, would require the United States to exercise effective military control over relevant Iranian territory or coastal areas, rather than simply maintaining naval forces in the waterway.

The presence of US warships or a blockade would therefore not, by itself, establish US sovereignty over the strait.

What does Trump's announcement mean?

Analysts say Trump's remarks are more likely to be political messaging than a literal announcement of an imminent change in the status of the waterway.

The comments come as Washington and Tehran remain at an impasse and as the administration faces domestic pressure over the cost and duration of the war.

By claiming that the United States could make the Strait of Hormuz its territory, Trump may be signalling that Washington does not intend to accept what it sees as a defeat in the conflict.

For now, however, the legal and practical barriers to annexing the strait remain substantial, while any attempt to change its status by force could further escalate a conflict already threatening one of the world's most important energy routes.