The move, which came just days before the United Nations will discuss and vote on an Arab peace plan aimed at ending the 10-month-old crisis, will nonetheless limit the options and time for Syrian President Bashar al-Assad, said He Wenping, a researcher with the Institute of West Asian & African Studies at the Chinese Academy of Social Sciences. 

Scheduled to send a delegation to New York to brief UN Security Council members, the 22-member Arab League said its latest decision resulted from escalating violence in Syria, where the UN says around 5,400 people have been killed since protests against the administration of Assad began last March. 

Expressing "surprise and regret" over suspension of the month-old mission, the state channel Syria TV quoted an unnamed official as saying: "This will have a negative impact and put pressure on (Security Council) deliberations with the aim of calling for foreign intervention and encouraging armed groups to increase violence." 

Although the bar has been raised for Assad, it is difficult for the UN to immediately intervene in the Syrian crisis, He said. 

"Struggles within the framework of the Arab League may still go on for a while It's not like a UN resolution will be passed any minute. It's definitely not that simple. Syria has friends at the UN, too," she said. 

Russia on Sunday slammed the Arab League's suspension. Its Foreign Minister Sergei Lavrov said Moscow "would like to know why they are treating such a useful instrument in this way". 

"I would support an increased number of observers," Lavrov was quoted as saying by the Russian ITAR-TASS news agency. 

The 100 or so Arab League observers will remain inside Syria, but will no longer visit any hotspots in the country. Damascus has stepped up attacks against opposition centers, including Homs and Hama and parts of the capital's suburbs, in the past week as it vowed to swipe out what it calls "terrorist attacks". 

On Saturday, Syrian Interior Minister Mohammed Shaar told families of security members killed in the protests that security forces "will continue their struggle to clean Syria's soil of the outlaws". The Syrian government claims that about 2,000 members of the security forces have been killed in the unrest. 

The Arab League's Secretary-General and Qatar's prime minister were set to leave for New York on Sunday to lobby support for the latest draft resolution, which, introduced by Morocco, calls for a two-month transition to a unity government, with Assad transferring powers to his vice-president. 

Syria has rejected the proposal, saying it violates its sovereignty.