Iran on Tuesday denounced U.S. President Barack Obama for keeping the "threat" of military force on the table to coerce the Islamic state into curbing its controversial nuclear activities.

"It is a source of regret that he still uses the language of threat after we told them to replace it with one of respect," Iranian Foreign Ministry spokeswoman Marzieh Afkham told reporters.

President Barack Obama said Monday that a U.S. deal reached with Russia at the weekend had the potential to end the threat of Syria's chemical arsenal.

In his first on-camera response to the breakthrough, Obama cautioned that the deal to identify and destroy the weapons must be properly implemented and that "we are not there yet."

U.S. President Barack Obama has said he and Iran's new President Hassan Rowhani have exchanged letters, and warned his reluctance to strike Syria had no bearing on U.S. threats of force to thwart an Iranian nuclear bomb.

Obama, in an interview aired on ABC News Sunday, confirmed the outreach to Rowhani for the first time, and said he believed the Syria chemical arms drama showed that diplomacy could work if backed by threats of military action.

Rebel fighters have expressed disdain for U.S. President Barack Obama after he backed away from striking over alleged chemical weapons attacks, saying the world does not care about Syria.

Leaders of two rebel brigades in the northern city of Aleppo, speaking to Agence France Presse after agreeing to join forces, also accused Russia and the regime of Bashar Assad of conspiring to buy time for the Syrian president to press his campaign against those seeking to overthrow him.

A pro-Kremlin lawmaker and former Olympic gold medalist faced a racism row Saturday after she posted a photo-collage of President Barack Obama juxtaposed with a banana on Twitter.

Irina Rodnina posted on Twitter a photomontage that purports to show Obama and his wife gazing at a hand in the foreground holding up a banana.

U.S. President Barack Obama welcomed the deal reached Saturday to strip Syria of chemical weapons but said much remains to be done and Damascus must comply with the accord.

In a statement, Obama said that if the regime of President Bashar Assad does not live up to the deal Washington reached with Syria's ally Russia, "the United States remains prepared to act."

Barack Obama will pay the first visit by a U.S. president to Malaysia in a half-century on a four-nation Asia tour next month, the White House said Friday.

Obama will attend summits in Indonesia and Brunei and also visit longtime U.S. ally the Philippines during the October 6-12 trip.

The U.N.'s top human rights body Friday urged U.S. Secretary of State John Kerry and Russian counterpart Sergei Lavrov to help a team probing rights' violations in Syria get access to the war-torn country.

Kerry and Lavrov, in Geneva to discuss how to neutralize Syria's chemical weapons and avert U.S.-led military strikes, should also consider how to help U.N. investigators enter the country, U.N. Human Rights Council president Remigiusz Henczel wrote in a letter to the two diplomatic heavyweights.

France has reassured President Michel Suleiman that a possible Western attack against the Syrian regime would neither target Lebanon nor Hizbullah, As Safir daily reported on Friday.

The daily's correspondent in Paris said French President Francois Hollande told Suleiman on the sidelines of the Francophone Games in the southern city of Nice that Paris was exerting all efforts to steer Lebanon clear of the developments linked to Syria and its chemical weapons.

Russian Foreign Minister Sergei Lavrov said Thursday that Syria handing over chemical weapons and joining the treaty banning them would make U.S. strikes against the country "unnecessary," as U.S. Secretary of State John Kerry rejected a 30-day timetable suggested by Syrian President Bashar Assad to begin submitting data on his chemical arsenal.

Lavrov told journalists ahead of talks with Kerry that their goal is to agree how to "solve once and for all the problem of chemical weapons in Syria" through the country's joining of the chemical weapons convention.