Iran's top diplomat Abbas Araghchi landed in Istanbul on Friday for talks where Türkiye was to offer help to mediate tensions with the United States, which has mooted a possible military strike.
During the visit, Araghchi was to hold talks with Turkish Foreign Minister Hakan Fidan and also meet with President Recep Tayyip Erdogan, Iran's foreign ministry said in a statement announcing his arrival.
It was not immediately clear at what time the talks would take place but the two ministers were to hold a news conference at 13:45 pm (1045 GMT), the Turkish authorities said.
Friday's visit comes hours after US President Donald Trump said he hoped to avoid military action against Iran, which has threatened to strike American bases and aircraft carriers in response to any attack.
For several weeks, Trump has been threatening to launch a military strike on Iran over its deadly protest crackdown earlier this month.
A US naval strike group has been in Middle Eastern waters since Monday and Trump warned it was "ready, willing and able" to hit Iran "if necessary".
Late on Thursday, Trump -- who had previously warned time was "running out" for Tehran -- appeared to slightly pull back, saying: "We have a group headed out to a place called Iran, and hopefully we won't have to use it."
Türkiye has repeatedly expressed its staunch opposition to military action and was to offer to mediate between Washington and Tehran in talks with Araghchi on Friday.
It is also considering measures to reinforce security along its border should the dispute escalate.
Fidan has urged the sides to return to the negotiating table and suggested Washington tackle outstanding issues with Iran "one-by-one", starting with the nuclear file rather than trying to address everything at once.
As well as Türkiye's diplomatic efforts to stave off a military confrontation, Erdogan has also been pushing Washington for a high-level trilateral meeting, Türkiye's Hurriyet daily, which is close to the government, reported on Thursday.
There was no official confirmation of the report.
Alongside its diplomatic push, Ankara is assessing additional security precautions along its 500-kilometer (310-mile) frontier with Iran, a senior Turkish official told AFP.
Türkiye began construction of a wall in 2021 and has so far built 380 kilometers (236 miles) of concrete barrier and 553 kilometers of trenches with nearly 250 surveillance towers.
