"Iran's military might has forced America to negotiate," headlines the Kayhan newspaper, whose editorial line has long opposed any compromise or negotiations with the United States.

The conservative daily has adopted a more conciliatory tone in recent days as the two countries -- foes since shortly after the 1979 Islamic Revolution -- reported progress during talks in Rome.

"Americans need us and the credibility that negotiations with Iran give them," wrote the newspaper, still describing US President Donald Trump as an "untrustworthy psychopath" and "unpredictable".

Iran maintains that there has been no direct interaction with the United States during the two rounds of talks on April 12 and 19, insisting that all communication has gone through Omani intermediaries.

State news agency IRNA said the Iranian stock market saw a "historic" boost on Saturday, while the rial strengthened on the black market, trading at around 830,000 to the dollar on Sunday -- down from over one million before the talks began.

Technical discussions between Iranian and US experts are scheduled for Wednesday in Oman, before further talks on Saturday between Foreign Minister Abbas Araghchi and the US envoy to the Middle East, Steve Witkoff.

Reformist daily Ham Mihan argued that direct negotiations are "neither useful and possible, nor logical" during the technical phase.

Reformist daily Shargh cautiously welcomed the progress of the talks, which it said allowed for "the gradual discovery of what the other side wants."

"Although in the course of negotiations, the parties have positions and red lines, new opportunities always emerge," the newspaper added.

Iran considers any discussion involving the complete dismantling of its nuclear program, its missiles or its support for armed groups hostile to Israel, including Hezbollah in Lebanon and the Huthis in Yemen, to be a "red line".

The US has long accused Iran of working toward aquiring an atomic bomb, something Tehran has repeatedly denied, insisting its nuclear programme is for peaceful purposes like the provision of energy.

The talks have raised hopes in Iran of an improvement in the economic situation.