Egyptian President Mohamed Morsi has no immediate plans to restore ties with Iran, his spokesman said in comments published Saturday ahead of a landmark visit to Tehran later this month for a Non-Aligned Movement summit.

"The matter (of restoring diplomatic ties) is out of the question at this stage," Yasser Ali told the Saudi-owned newspaper Al-Sharq Al-Awsat in an interview also carried by Egyptian media.

A senior U.S. lawmaker called for diplomatic repercussions on Washington's ties with Iraq and Afghanistan if the countries do not cooperate on curbing Iran's nuclear ambitions.

Ileana Ros-Lehtinen, who chairs the House Foreign Affairs Committee, asked Pentagon chief Leon Panetta and Treasury Secretary Timothy Geithner to detail what measures are being taken to prevent Tehran's efforts to bypass sanctions through financial dealings brokered by Iraq and Afghanistan.

The U.N. atomic watchdog said that "intensive" talks Friday with Iran had failed, with no plans for a follow-up meeting to persuade Tehran to address evidence of suspected nuclear weapons research.

"As in our last meeting in June we intended to finalize a structured approach paper that has been under discussion for many months," International Atomic Energy Agency chief inspector Herman Nackaerts said after the meeting in Vienna.

A month after the suicide bombing of an Israeli tourist bus in Bulgaria, investigators have made no major breakthroughs but progress has been encouraging, the country's interior minister told Agence France Presse Friday.

"It is only expected that it will take time, sometimes years, to uncover the whole mechanism behind the attack. But we are encouraged by the work we accomplished in the last 30 days," Tsvetan Tsvetanov said in an interview.

Iran's supreme leader, Ayatollah Ali Khamenei, dismissed Saturday U.S. allegations of a Tehran-sponsored assassination plot as "absurd," in his first direct reaction to the claim.

"It's a meaningless and absurd accusation regarding a number of Iranians," he told a crowd in the western city of Gilangharb in a speech carried by state television.

The United States took a renewed swipe at Iran Monday, telling the annual gathering of the U.N. atomic agency Tehran was creeping "still closer" to producing nuclear weapons-grade uranium.

"Iran has continued to engage in a longstanding pattern of denial, deceit and evasion," U.S. Energy Secretary Steven Chu told the 151-nation International Atomic Energy Association (IAEA) general conference in Vienna.

The Iranian intelligence ministry said on Saturday that it had made 30 arrests as it dismantled a network suspected of spying for the United States on its basic infrastructure as well as its nuclear and defense research.

"Due to the massive intelligence and counter-intelligence work by Iranian intelligence agents, a complex espionage and sabotage network linked to America's spy organization was uncovered and dismantled," a ministry statement read out on state television said.

Radical Shiite cleric Moqtada al-Sadr has returned to Iran after having only arrived in Iraq around two weeks ago, two senior officials within his movement said Saturday.

"He left Iraq on Thursday to go back to Iran," an aide to the firebrand cleric told Agence France Presse. "That's all we can tell you."