The United Arab Emirates pulled out of US-led air strikes on Islamic State positions partly because it thought they could not succeed without a push to arm Sunni Muslim tribes in Iraq, a newspaper close to the government said.

The UAE's decision to withdraw its planes, reported by US officials after a Jordanian pilot was shot down over Syria on Dec. 24, raised fears that regional support for the coalition air campaign might be slipping.

The UAE has not commented on the reports of its decision but U.S. officials said it was concerned about pilots' safety; Islamic State released a video this week purporting to show it burning Jordan's First Lieutenant Mouath al-Kasaesbeh to death.

Al-Etihad newspaper said on Friday that was only part of the reasoning.

"The other important part behind the UAE's reservation ... was its discontent with the coalition which has not kept its promise in supporting the Sunnis in Anbar, not preparing them, equipping them and arming them to take part in the war against Daesh," the newspaper's editor-in-chief, Mohammed al-Hammadi, wrote in an editorial.

"Neither the air strikes nor the media war are enough to defeat Daesh," said the paper, using a pejorative Arabic acronym for Islamic State.

Etihad reported that UAE officials had brought up their concerns about the failure to arm Sunni tribes at a meeting of countries supporting the coalition in London

"The UAE said: 'the main point is what we have expressed in the last London conference -- coalition against Daesh -- about the continuation of not empowering the Sunni tribes in Anbar province despite the promises to do so'," the paper reported.

It did not give any details on the source of its information.

Tribes in Iraq's western Anbar province, which borders Jordan, Syria and Saudi Arabia, are divided. Some have chosen to join the hardline Sunni Muslim fighters of Islamic State, while others are fighting the group.

The fall of large parts of Anbar province to Islamic State poses a major security risk for its neighbours.

The United States has said the coalition includes more than 60 countries, carrying out various tasks, including military attacks, humanitarian support, propaganda and cracking down on Islamic State's finances.

Washington says Saudi Arabia, Qatar, Jordan and Bahrain have also participated in or supported air strikes in Syria. Australia, Britain, Canada and France have joined US operations against Islamic State targets in Iraq.-Reuters