Syria faced new sanctions after flouting Sunday an Arab League deadline to accept observers to monitor the unrest sweeping the country, which the UN says has killed at least 4,000 people.
The latest standoff between Syria and the Arab League comes as the death toll from violence across the country on Saturday and Sunday rose to at least 63, and after the UN Human Rights Council accused Damascus of "gross violations" of human rights.
A senior Qatari official said Damascus had asked for "new clarifications and further amendments to be made to the protocol which was proposed" to cover the deployment of the observer mission.
But the Arab ministers had "refused."
The Qatari official said, however, that if Syrian officials "still want to sign, they can come tomorrow to Cairo."
The Arab League ministerial committee late on Saturday gave Damascus until Sunday to allow an observer mission into the country and thereby avoid further sanctions.
Jeffrey Feltman, US assistant secretary of state for near eastern affairs, said monitors were needed to keep a check on the forces of Syrian President Bashar al-Assad who have been accused by the UN of rights abuses.
"We believe that in full light of monitors and media, the security services reporting to Assad and his clique would not be able to operate the way they are operating now," Feltman said in Jordan.
Allowing in monitors would be a "peaceful way of trying to stop this sustained cycle of violence that Assad seems committed to turning Syria into."
Feltman also charged that Syria's ally Iran was "actively engaged" in supporting the Syrian regime's lethal crackdown and "facilitating" the killings of Syrian people.
The meeting in Doha listed 19 Syrian officials it said would be banned from travel to Arab countries and whose assets would be frozen by those states.
The panel also called for an embargo on the sale of Arab arms to Syria and cut by half the number of Arab flights into and out of Syria -- including its national carrier Syrian Air -- with effect from December 15.
Top military and intelligence brass as well as the defence and interior ministers are among the 19 officials banned from travel to Arab countries.
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President Assad's brother, General Maher al-Assad, who heads the feared Fourth Armoured Division, and his cousin Rami Makhluf, a telecommunications tycoon, are also among those blacklisted.
The Arab panel also tasked a committee with drawing up a list of Syrian businessmen involved in financing the repression, ahead of slapping them with sanctions.
"This is a message to businessmen who have kept silent, so that they will choose what side to be on," said Najib Ghadban, a member of the opposition Syrian National Council which represents most of Assad's opponents.
An analyst in Damascus said chances were slim that the government would allow in observers under the conditions set by the Arab League. Syria says the conditions undermine its sovereignty.
The Arab League had on November 27 approved an initial wave of sweeping sanctions against Assad's government over the crackdown -- the first time that the bloc has enforced such punitive measures against a member state.
Those measures included an immediate freeze on transactions with Damascus and its central bank and of Syrian regime assets in Arab countries.
On the ground, three children aged 11, 14 and 16 and their father, were among 40 people killed across Syria on Sunday by security forces and pro-regime "shabiha" militiamen, the Syrian Observatory for Human Rights said.
At least 30 of those killed died in the flashpoint central province of Homs which has been at the forefront of the regime's crackdown on dissidents, and included mutinous soldiers, the Britain-based watchdog said.
Earlier it reported 11 civilians among 23 people killed on Saturday, most occurring in the northwestern province of Idlib, another focal point of anti-regime protests raging since March.
Sunday's deadline was announced in Doha by Qatari Prime Minister Sheikh Hamad bin Jassim al-Thani, who also warned against the internationalisation of the Syrian crisis if Damascus did not heed the Arab call.
"As Arabs we fear that if the situation continues things will get out of Arab control," Sheikh Hamad said.
On Friday an emergency meeting of the UN Human Rights Council passed a resolution "strongly condemning the continued widespread, systematic and gross violations of human rights and fundamental freedoms by the Syrian authorities."
Damascus rejected the resolution as "unjust" and said it was "prepared in advance by parties hostile to Syria."