Deadlocked talks with Iran will be in focus at a meeting of the U.N. nuclear agency's board from Monday, together with a possible new term for director general Yukiya Amano.

Western powers, however, are expected to refrain from upping the ante against Tehran at the meeting in Vienna in order not to jeopardize parallel diplomatic efforts by six world powers, diplomats said.

U.N. Secretary-General Ban Ki-moon said Friday that the ball remained in Iran's court over its contested nuclear program, though he was encouraged by new feelers being put out by Tehran and the West.

"I am encouraged that, at their recent talks in Almaty, the P5+1 and Iran agreed on dates and venues for further meetings soon," Ban told reporters in Geneva.

A prominent Iranian security chief was present in Lebanon at the time of the assassination of Internal Security Forces Intelligence Bureau chief Brigadier General Wissam al-Hasan last year, al-Joumhouria newspaper reported on Friday.

According to the newspaper, Brigadier “Hindawi,” one of Iran's elite Quds Force who is close to the commander of the Force General Qassem Suleimani, was in Lebanon when the assassination occurred.

Iran was "interested" by updated proposals from world powers to break a stalemate over its suspect nuclear program, and must now take concrete steps to move forward, a U.S. official said Wednesday.

Characterizing two-day talks in Kazakhstan as "useful," State Department acting deputy spokesman Patrick Ventrell said "the onus is absolutely on Iran."

Former president Ali Abdullah Saleh affirmed his support on Wednesday for Yemen's unity in the face of calls by southerners for secession, which he said are backed by Iran.

"No to secession... Our people in the south are with unity," Saleh said in a rare public appearance in Sanaa's Sabiin Square before thousands of supporters.

Iran and world powers agreed on Wednesday to hold new talks in March and April over the Islamic republic’s disputed nuclear drive, with Tehran hailing a "more realistic" approach by their counterparts at two days of talks in Kazakhstan.

There was no sign of a breakthrough in the decade-long deadlock over Iran's nuclear ambitions in the Kazakh city of Almaty but the agreement on new meetings suggested there was still potential for progress.

Iran said Saturday it is investigating the reported defection of one of its diplomats in Norway, with a spokesman suggesting it was due to personal problems, Mehr news agency said.

"Despite completing his mission, an administrative staffer at our embassy in Oslo has not yet returned to Tehran due to some personal problems, such as his child's education and family problems," said the foreign ministry's Ramin Mehmanparast.

Iran said Saturday it will not go beyond its obligations nor accept anything outside its rights under the non-proliferation treaty, ahead of talks with major powers over its disputed nuclear drive.

"We will not accept anything beyond our obligations and will not accept anything less than our rights," said the Islamic republic's top nuclear negotiator, Saeed Jalili, quoted by ISNA news agency.

Former Prime Minister Saad Hariri criticized on Thursday the government's silence over Hizbullah members' alleged fighting in Syria alongside regime forces.

He slammed in a statement “the unconscious government's allowing of Hizbullah to jeopardize national security through its intervention in the conflict.”

A top Iranian envoy said Wednesday that increased Western pressure over his country's nuclear program could end hopes for a negotiated settlement.

Ahead of key new negotiations in Kazakhstan on Tuesday, Iran's U.N. Ambassador Mohammad Khazaee said that his country wants talks, but hit out at Western tactics of sanctions along with engagement.