Warning of "enormous" dangers, Kuwait urged Arab leaders on Tuesday to end multiple disputes complicating crises such as Syria's war and political turmoil in the most populous Arab state, Egypt.

Kuwait's emir, Sheikh Sabah Al-Ahmed Al-Sabah, called on the annual meeting of the 22-member League of Arab States to solve rifts he said were obstructing joint Arab action.

"The dangers around us are enormous and we will not move towards joint Arab action without our unity and without casting aside our difference," Sheikh Sabah, the summit host, said.

He named no specific country, but was apparently referring to worsening disputes among Arab states over the political role of Islamists in the region, and over what many Gulf states see as interference in their affairs by non-Arab Iran.

The meeting is expected to agree on more humanitarian action in response to Syria's war, which has entered its fourth year and put a severe strain on neighbouring states hosting refugees.

Saudi Crown Prince Salman Bin Abdulaziz Al Saud, whose country supports rebels trying to topple Syrian President Bashar Al-Assad, called for "changing the balance of forces" on the ground there. He said the crisis in Syria had reached catastrophic proportions.

The gathering follows an unusual row among members of the Gulf Cooperation Council (GCC) alliance of Gulf Arab states over Qatari support for Egypt's Muslim Brotherhood, and a verbal spat between Iraq and Saudi Arabia over violence in Iraq's Anbar province.

The row among Gulf states is unlikely to get a detailed airing at Tuesday's plenary gathering.

Gulf states tend to keep their disagreements private, making a decision by Saudi Arabia, the UAE and Bahrain earlier this month to recall their ambassadors from Qatar especially sensitive.

Kuwait, which kept its envoy in Doha, has offered to mediate in the dispute and is anxious to see the summit take place without further divisions.

Shortly before the gathering began Kuwait's Sheikh Sabah, smiling broadly, stood between Saudi Crown Prince Salman and Qatar's emir, Sheikh Tamim bin Hamad al-Thani, holding hands with them in an apparent attempt to convey a mood of reconciliation.

"WOUND IS DEEP"

Asked whether the issue would be raised at the meeting, Khaled Al Jarallah, Kuwaiti undersecretary for foreign affairs, told reporters: "Gulf reconciliation, and Gulf issues are something for inside the Gulf house."

On Monday Lebanon's foreign minister called on Arab states to support the Lebanese army to counter fallout from Syria's civil war, which he said threatened to tear the country apart.

Arab summits have long been dominated by the Israeli-Palestinian conflict, a topic on which most Arab states share a common view. The "Arab Spring" uprisings that began in 2011 have polarised the region, however.

Syria's war has stirred tensions between Sunni Muslims, notably in the Gulf, and Shi'ites in Iraq, Lebanon and Iran, whose faith is related to that of Assad's Alawite minority.

Arab League Secretary-General Nabil Elaraby has said the summit could be affected by "differences" and that there was an urgent need to clear the atmosphere.

Egypt's Foreign Minister Nabil Fahmy said reconciliation would prove difficult at the summit. "I don't expect we will leave from the Kuwait summit with all parties convinced that all things are resolved," he told reporters in Kuwait on Sunday. "The wound is deep."

Syrian opposition leaders have been lobbying the Arab League to give them Syria's seat on the pan-Arab body, and to push Arab states to approve the delivery of military hardware to them to boost their fight against Assad.

Syria's seat will remain vacant at the summit but the head of the opposition Syrian National Coalition, Ahmed Al-Jarba, is due to deliver a speech. - Reuters