Yemeni Foreign Minister Riyadh Yassin on Monday rejected Iran's offer to mediate a solution to the crisis in his war-torn country, insisting that Tehran-backed rebels surrender.

"Any mediation effort coming from Iran is unacceptable because Iran is involved in the Yemen issue," Yassin said on the sidelines of an Arab-Turkish economic meeting in Kuwait City.

Australia and Iran will share intelligence to track foreign fighters working with the Islamic State group in Iraq, Foreign Minister Julie Bishop said Monday, as lawmakers urged caution.

In the first trip to Iran by an Australian minister in more than a decade, Bishop said it would be an informal arrangement.

Afghanistan and Iran announced Sunday plans for enhanced security cooperation to combat threats from the Islamic State group, including possible joint military operations.

Standing alongside visiting Afghan leader Ashraf Ghani, Iran's President Hassan Rouhani said the tumult hitting the region meant intelligence must be shared.

With conflicts raging across the Middle East, the U.S. is seeking to reassure its Gulf allies that it has a regional strategy which will be bolstered, not shredded, by any Iran nuclear deal.

The U.S. administration appears increasingly caught in a game of whack-a-mole as it confronts a series of complex challenges, with Saudi-led airstrikes in Yemen just the latest complication in a regional tinderbox pitting Sunnis against Shiites, and even Sunni against Sunni.

Australia's foreign minister on Saturday hailed Iran's efforts to crush the jihadist Islamic State group in Iraq, saying on a rare trip to Tehran that the militants can be defeated.

Julie Bishop is Australia's highest-ranking official to visit Iran in 12 years and she discussed the conflict in Iraq with her Iranian counterpart Mohammad Javad Zarif.

Iran is ready to resume nuclear enrichment "without any limitations" unless sanctions are totally and immediately removed at the end of negotiations, Foreign Minister Javad Zarif said Friday. 

Speaking to TV channel Euronews in Lisbon, Zarif said: "We can have the path of confrontation or we can have the path of co-operation, we cannot have a little bit of each."

Al-Mustaqbal movement leader ex-PM Saad Hariri on Friday accused Hizbullah chief Sayyed Hassan Nasrallah of “falsification and deception” regarding the Yemeni conflict, noting that Hizbullah's Yemen rhetoric is “imported from Iran” and does not serve Lebanon's interest.

“Following in the footsteps of (Iran's supreme leader) Sayyed Ali Khamenei, Sayyed Hassan Nasrallah has excelled in falsification, deception and the shows of intimidation and sectarian mobilization,” said Hariri via Twitter, only minutes after Nasrallah launched scathing tirades against Saudi Arabia over its Arab-backed airstrikes in Yemen.

Two suspected al-Qaida militants were killed overnight in Yemen in a drone strike believed to have been carried out by the United States, a tribal source said on Friday.

The late night strike targeted a vehicle in Habban, southeast of Ataq, the  main town in southern Shabwa province.

Australian Foreign Minister Julie Bishop visits Iran at the weekend looking for Tehran to take back failed asylum seekers, but the rare trip also has deeper significance as the West seeks to seal a deal to rein in the Islamic state's nuclear ambitions.

The first visit to Shiite Iran by an Australian foreign minister in 12 years follows the framework political agreement reached last month under which Tehran would accept strict nuclear controls in return for the easing of damaging economic sanctions.

The delivery of Russian S-300 air defense missiles to Iran will not affect America's ability to strike at Tehran's nuclear facilities if necessary, the top U.S. military officer said Thursday.

"We've known about the potential for that system to be sold to Iran for several years and have accounted for it in all of our plans," General Martin Dempsey, chairman of the U.S. Joint Chiefs of Staff, told a news conference.