Iran and the United States sent mixed signals on Tuesday about resolving their disputes as Iran’s supreme leader threatened to further breach the 2015 nuclear deal while the U.S. president cited “a lot of progress.”

Iranian navy vessels came to the assistance of a disabled foreign oil tanker in the Gulf that needed repairs, Iran's foreign ministry spokesman was quoted as saying on Tuesday by the semi-official news agency ISNA.

U.S. President Donald Trump said on Tuesday a lot of progress had been made with Iran and that he was not looking for regime change in Iran.

Britain will send a third warship to the Persian Gulf, though the move is not related to the current Iran crisis, the Ministry of Defence (MoD) said on Tuesday.

The United Nations told the United States it is concerned by tight travel restrictions on Iranian Foreign Minister Mohammad Javad Zarif during his visit to New York this week, U.N. spokesman Farhan Haq said on Monday.

Gibraltar police said on Friday that all four crew members of the Iranian Grace 1 tanker have been released on bail without charge after it was detained last week on suspicion of breaking European sanctions by taking oil to Syria.

Britain does not intend to escort every British-flagged merchant vessel through the Strait of Hormuz, a security source said on Thursday, after a Royal Navy warship had to stop three Iranian vessels from blocking the passage of a BP-operated tanker.

Gibraltar police said they have arrested the captain and chief officer of the detained Iranian Grace 1 supertanker accused of violating EU sanctions on Syria and have seized documents and electronic devices from the vessel.

French President Emmanuel Macron's top diplomatic advisor met with Iran's president Wednesday winding up a day of talks in Tehran aimed at saving a landmark 2015 nuclear deal and easing tensions between Tehran and Washington.

Five boats believed to belong to Iranian Revolutionary Guards approached a British oil tanker in the Gulf on Wednesday and asked it to stop in Iranian waters close by, but withdrew after a British warship warned them, U.S. officials said.

Three members of Iran's elite Revolutionary Guards were shot dead in the western city of Piranshahr on Tuesday, the semi-official Tasnim news agency reported, citing a Guards statement.

French President Emmanuel Macron's top diplomatic advisor will travel to Iran on Tuesday and Wednesday to try to de-escalate tensions between Tehran and the United States, a presidential official said on Monday.

Iran has enriched uranium beyond a 3.67% purity limit set by its deal with major powers, the U.N. nuclear watchdog policing the deal said on Monday, confirming a move previously announced by Tehran.

Iran threatened on Monday to restart deactivated centrifuges and ramp up enrichment of uranium to 20% purity in a move away from the 2015 nuclear deal, but the head of Iran's Revolutionary Guards insisted the world knows Tehran is not pursuing nuclear arms.

The UN's nuclear watchdog said Friday it will hold a special meeting on Iran's nuclear programme next week, days after Tehran breached one of the limits set in a 2015 deal with world powers.

An Iranian Revolutionary Guards commander threatened on Friday to seize a British ship in retaliation for the capture of an Iranian supertanker by Royal Marines in Gibraltar.

U.S. President Donald Trump warned Iran Wednesday its threats could "come back to bite" after Tehran vowed to exceed the maximum uranium enrichment level allowed by a landmark 2015 nuclear accord.

British Royal Marines seized a giant Iranian oil tanker in Gibraltar on Thursday for trying to take oil to Syria in violation of EU sanctions, a dramatic step that drew Tehran's fury and could escalate its confrontation with the West.

The diplomatic chiefs of the EU, France, Germany and Britain said Tuesday they were "extremely concerned" and urged Iran to reverse its decision to breach a limit on enriched uranium reserves under a 2015 nuclear deal.

Iran's main demand in talks aimed at saving its nuclear deal is to be able to sell its oil at the same levels that it did before Washington withdrew from the accord a year ago, an Iranian official said on Thursday.