Iranian Foreign Minister Abbas Araghchi will meet with Russian President Vladimir Putin in St. Petersburg during his scheduled trip to Russia Monday, according to Iran’s ambassador to Russia, Kazem Jalali.

"In continuation of the diplomatic jihad to advance the country's interests and amid external threats, the Foreign Minister of the Islamic Republic of Iran will meet with the President of Russia during his trip to St. Petersburg," Jalali said in a post on X Sunday afternoon.

It was a busy weekend for Araghchi, who traveled to Oman once and Pakistan twice before heading to Russia Sunday evening.

Iran’s semi-official news agencies Fars and ISNA reported that Tehran conveyed written messages to the U.S. via Pakistani mediators, letters that addressed some of Iran’s “red lines,” including issues related to its nuclear program and the blockade of the Strait of Hormuz.

-ABC News' Claire Bower

Iran’s main news agency IRNA reports that the country’s top diplomat, Foreign Minister Abbas Araghchi, departed Islamabad, Pakistan, late Sunday for Moscow, where he’ll discuss regional developments and bilateral Iran-Russia relations with senior Russian officials.

Iran’s Ambassador to Moscow Kazem Jalali also posted on Telegram that Araghchi hopes to meet with Russian President Vladimir Putin during his visit Monday.

-ABC News' Claire Bower and Anna Sergeeva

Iranian media reports that Foreign Minister Abbas Araghchi has conveyed written messages to the United States via Pakistan during his recent regional tour.

According to Iran's semi-official Fars News Agency, the messages outline Tehran’s “red lines” in peace negotiations, including issues related to its nuclear program and the Strait of Hormuz.

Fars added that the exchange of messages does not constitute negotiations but is an “initiative” by Iran to clarify the situation in the region and the country’s red lines.

Meanwhile, the semi-official Tasnim News Agency reported that Araghchi has returned to Islamabad to continue consultations with Pakistani officials, and that the visit is not related to nuclear talks.

Tasnim said conveying Iran’s conditions for ending the war to Pakistan, the government of which is acting as a mediator, is one of the “key objectives” of the trip.

Araghchi would discuss the legal status of the Strait of Hormuz, compensation, guarantees against further military action, and the lifting of the naval blockade of the Strait of Hormuz, according to Tasnim.

-ABC News' Maryam Rahimi

Iran’s foreign minister, Abbas Araghchi, arrived in Islamabad Sunday following talks with Oman’s sultan in Muscat as regional diplomatic efforts to end the war continue, according to Iran's semi-official Tasnim News Agency.

Araghchi first arrived in Islamabad on Friday evening and met with Pakistan’s prime minister, foreign minister and army chief, in what Iranian media described as an effort to convey Tehran’s position on the conflict.

Tasnim also reported that Araghchi held phone calls with his Qatari and Saudi counterparts to discuss developments surrounding the ceasefire and ongoing diplomatic efforts related to the conflict between Iran and the U.S.

Oman has for years acted as a back channel for different negotiations between Tehran and Washington.

Since the U.S.-Israeli attacks on Iran began on February 28, Iran has launched strikes against several countries in the region, including Qatar and Saudi Arabia. Both countries are influential Arab states with close ties to the U.S., despite not being direct parties to the conflict.

-ABC News' Maryam Rahimi

President Donald Trump said in a post on his social media platform Sunday afternoon that the U.S. Navy had attacked an Iranian-flagged cargo ship in the Gulf of Oman and that U.S. Marines have taken custody of the vessel.

“Today, an Iranian-flagged cargo ship named TOUSKA, nearly 900 feet long and weighing almost as much as an aircraft carrier, tried to get past our Naval Blockade, and it did not go well for them,” Trump said in the post.

U.S. Central Command confirmed that the destroyer USS Spruance intercepted the Touska as it transited the North Arabian Sea towards the Iranian port of Bandar Abbas. 

After repeated warnings over a six-hour timespan, the destroyer warned the Touska’s crew to vacate the engine room and fired several rounds at that location from its five-inch gun, according to CENTCOM.

Marines later boarded the ship, and it remains in U.S. custody, CENTCOM said.

It appears to be the first instance of the U.S. attacking and seizing a merchant vessel since it instituted the blockade of Iranian ports.

The president further wrote that "U.S. Marines have custody of the vessel," which he said is "under U.S. Treasury Sanctions because of their prior history of illegal activity. We have full custody of the ship, and are seeing what’s on board!"

The move comes after Joint Chiefs Chairman Gen. Dan Caine warned that the U.S. would actively enforce the blockade on Iranian-flagged vessels around the globe.

"In addition to this blockade, the joint force, through operations and activities in other areas of responsibility, like the Pacific area of responsibility under the command of Admiral Paparo, will actively pursue any Iranian-flagged vessel or any vessel attempting to provide material support to Iran. This includes Dark Fleet vessels carrying Iranian oil," Caine said in a Pentagon press conference Thursday.

-ABC News' Nicholas Kerr