Iranian Foreign Ministry spokesman Abbas Mousavi said Sunday that the Iranian tanker Adrian Darya 1 has unloaded its oil cargo at a Mediterranean port, official IRNA news agency reported.

"We had already said that we would sell our oil, and acts of vexation would have no effect on our plans," said Mousavi.

"The tanker has gone to its destination, the oil has been sold," Abbas Mousavi said, speaking to the state television station without disclosing whether the crude oil had been delivered. 

He also stated that the U.S. pressure to seize the Iranian oil tanker was a violation of international maritime regulations, and such measures will only cause "trouble for those who take them."

Adrian Darya 1 went dark last week and was later photographed by a satellite near the Syrian port of Tartus.

"We will continue to put pressure on Iran and as President (Trump) said, there will be no waivers of any kind for Iran's oil," Reuters quoted Sigal Mandelker, U.S. Treasury Under Secretary for Terrorism and Financial Intelligence, as saying.

Iran: Seized British oil tanker would be released 'soon'

Meanwhile, the country also said on Sunday that the seized British-flagged oil tanker Stena Impero would be released in the coming days, official IRNA news agency reported.

Legal procedure concerning the British oil tanker is about over and "we hope it will be released in the near future," Mousavi was quoted as saying.

Iran detained the Stena Impero on July 19 on the allegations that it had violated the maritime regulations while passing through the Strait of Hormuz.

Last Wednesday, Iran released seven crew members of the oil tanker.

The Iranian officials have ruled out any link between Stena Impero's case and British seizure of the Iranian supertanker Grace 1 off the coast of Gibraltar.

Tanker Grace 1, which was renamed by the Iranian authorities as Adrian Darya 1, was captured by British Royal Marines in Gibraltar on July 4, reportedly under the U.S. pressure, for allegedly violating EU sanctions against Syria, a charge denied by Tehran.

The ship was released by the Gibraltar authorities on August 16 and was later blacklisted by Washington.

The acting director general of the International Atomic Energy Agency (IAEA) arrived in Tehran on Sunday for talks with Iranian officials on the country's nuclear program, state-run IRNA news agency reported.

Cornel Feruta held talks with Ali Akbar Salehi, head of the Atomic Energy Organization of Iran, on the transparency of the Iranian nuclear program and the IAEA monitoring tasks at the country's nuclear sites.

"Unfortunately the European parties have failed to fulfill their commitments... The deal is not a one-way street and Iran will act accordingly as we have done so far by gradually downgrading our commitments," said Salehi.

"Iran will continue to reduce its nuclear commitments as long as the other parties fail to carry out their commitments," Salehi said, speaking after meeting Feruta.

Feruta is also scheduled to hold meeting with Iranian Foreign Minister Mohammad Javad Zarif on Sunday.

Feruta's visit to Tehran follows Iran's suspension of parts of its commitments to the 2015 nuclear deal, known as Joint Comprehensive Plan of Action (JCPOA). It also comes before a quarterly meeting of the IAEA's 35-country board of governors in Vienna on Monday.

"The actions they have taken are negative but not definitive. They can come back (to full compliance) and the path of dialogue is still open," French Foreign Minister Jean-Yves le Drian said on Sunday.

On Saturday, Iran officially announced a move to withdraw from part of its commitments to the JCPOA.

Following the announcement, Iran started up advanced centrifuges and activated 20 IR-4 centrifuges and 20 IR-6 centrifuges to boost the country's stockpile of enriched uranium.

Read more: 

Iran starts up advanced uranium enrichment centrifuges

Rouhani: Iran to develop centrifuges for faster uranium enrichment from Sept. 6

Iran gives new knock to nuclear deal but it's not yet broken

(With input from Reuters, Xinhua News Agency)