US President Donald Trump has said Washington has “total control” of the Strait of Hormuz and will maintain its naval blockade of Iran, as a senior Revolutionary Guards adviser suggested Tehran could prolong the war until Trump leaves office.

The competing statements came as Pakistan stepped up efforts to revive negotiations and conflicting accounts emerged over whether an interim agreement reached in June could be extended.

Trump said the United States had full control of the strategic waterway and that there was “nothing Iran can do about it”. Earlier this week, he described the US blockade of Iranian ports as a “steel wall”, saying Washington was allowing other vessels through the strait while preventing shipping from reaching Iran.

US Central Command said on Wednesday that American forces had redirected 59 commercial vessels, disabled three and boarded two as part of enforcement of what it also called the “steel wall blockade”.

The US account of control over the strait is disputed by Tehran, which continues to assert authority over shipping routes there. Iran's Revolutionary Guards said last week that reopening the waterway depended on Washington accepting Iranian conditions rather than the outcome of separate discussions with Oman.

Mohammad Reza Naghdi, a senior adviser to Revolutionary Guards commander Ahmad Vahidi, said Iran could pursue a war of attrition lasting beyond Trump's presidency.

“One way is to prolong this war until we get to the next term of the presidency and cause attrition, so that if anyone else wants to attack Iran, they will know there is a cost,” Naghdi told PBS NewsHour on Tuesday.

He said Tehran's objective was to establish sufficient deterrence to prevent further attacks on Iran.

Naghdi also defended Iranian action against civilian vessels attempting to cross the Strait of Hormuz, saying that during wartime Iran considered itself entitled to control routes it regarded as a threat.

His comments came as diplomatic efforts produced sharply contradictory accounts over the status of the interim agreement signed in June.

A senior Iranian official told Reuters on Wednesday that Tehran and Washington had not discussed extending the arrangement, contradicting a report by Turkey's Anadolu news agency citing Pakistani government sources.

“There is no talk of an extension because, from Iran’s perspective, there is no period that began and therefore nothing to extend,” the Iranian official told Reuters.

The official said Tehran considered Washington to have violated the interim agreement 48 hours after it was reached and withdrawn from it several days later.

The June agreement had provided a 60-day period for negotiations towards a broader settlement. Pakistan's National Assembly subsequently adopted a resolution welcoming the agreement and praising Pakistani officials involved in mediating between Washington and Tehran.

The Iranian source said current discussions through mediators instead concerned a possible US return to the interim agreement and a timetable for implementing its commitments, adding that there had been “absolutely no progress” on that issue.

Pakistan has continued its diplomatic push. Iranian Foreign Minister Abbas Araghchi met Pakistani Interior Minister Mohsin Naqvi in Mashhad on Wednesday, their second consecutive day of talks, according to Iran's state-run IRNA news agency.

Neither Washington nor Tehran has publicly confirmed the reported extension, leaving the status of the June agreement unresolved as Pakistani mediation continues.