U.S. Secretary of State John Kerry arrived in Abu Dhabi late Monday for talks on Syria and the Middle East hours after criticizing Russia for "enabling" the Assad regime.

Arriving from Jakarta on the sixth day of his latest diplomatic tour, Kerry began a meeting with Abu Dhabi's Crown Prince Mohammed bin Zayed and Foreign Minister Abdullah bin Zayed. He is expected to join them later for dinner.

The United Arab Emirates have expelled eight Kuwaiti students from two universities for forming a union, collecting donations and holding unauthorised meetings, an higher education official said.

The expulsion is a rare move against students from a fellow Gulf country.

Russia and Egypt are nearing a $3-billion arms purchase agreement that will be financed by Saudi Arabia and the United Arab Emirates, a Moscow newspaper reported on Friday.

The two sides have already either "initialed or signed" contracts for Egypt's purchase of Mig-29 fighters, air and coastal defense systems, Mi-35 attack helicopters and smaller arms, the Vedomosti daily quoted two Russian government sources as saying.

Fearful of Arab Spring-inspired unrest, Gulf monarchies have stepped up efforts to monitor and control the media, particularly online, Reporters Without Borders (RSF) said Wednesday.

Saudi Arabia, which is on the group's "Enemies of the Internet" list and ranks 164 out of 179 on its 2014 World Press Freedom Index, has been particularly aggressive in policing the Internet, including by arresting those who post critical articles or comments, it said.

Armed forces chief of staff General Hassan Firouzabadi has warned the Islamic republic's arch-foes that Iran is prepared for a "decisive battle" if attacked, Fars news agency reported on Wednesday.

"We are ready for the decisive battle with America and the Zionist regime (Israel)," Fars quoted Firouzabadi as saying.

A U.N. expert on Wednesday urged an independent probe into allegations of torture in United Arab Emirates prisons, which she was not allowed to visit during a fact-finding mission.

Gabriela Knaul, the U.N. Special Rapporteur on the Independence of Judges and Lawyers, also criticized "violations" and a "lack of transparency" in court proceedings in the Gulf country, where dozens of Islamists have been rounded up.

UAE President Sheikh Khalifa bin Zayed al-Nahyan has undergone an operation after suffering a stroke and is in a stable condition, the ministry of presidential affairs said Saturday.

Sheikh Khalifa suffered a stroke on Friday "that led doctors to operate (on) him... He is in a stable condition," the ministry said in a statement carried by state news agency WAM.

Human Rights Watch hit out at the United Arab Emirates for preventing it from holding a news conference Thursday to release a report criticizing rights violations in the Gulf state.

"Blocking Human Rights Watch from holding a news conference in the UAE sadly underscores the increasing threat to freedom of expression in the country," said Sarah Leah Whitson, HRW's chief for the Middle East and North Africa.

A court on Tuesday jailed a group of 30 Emiratis and Egyptians to terms ranging from three months to five years for forming a Muslim Brotherhood cell, a judicial source said.

The cell comprised 10 Emiratis and 20 Egyptians, including six who remain at large and were sentenced in absentia. The Egyptians will be deported after serving their sentences, the source told Agence France Presse.

Saudi Arabia and the UAE gave their backing Sunday to a decision by Syria's main opposition to join peace talks in Switzerland, which both Gulf states said must lead to regime overthrow.

The so-called Geneva II meeting starting on Wednesday aims to set up a transitional government to end an almost three-year war estimated to have killed more than 130,000 people and forced millions from their homes.