The European Union approved a fresh round of sanctions against Damascus on Monday, as Syria rejected an Arab League call for President Bashar al-Assad to step down in favour of a unity government, dpa reported.
A Syrian official, quoted by the state-run SANA news agency, described the new Arab League plan as a "conspiracy against Syria." The League had advised al-Assad to hand power to a deputy.
"Syria rejects the decisions of the Arab League ministerial council ... and considers them a violation of its national sovereignty and a flagrant interference in its internal affairs," the official said.
On Sunday, Arab League foreign ministers proposed calming the unrest that has gripped the country since March by having al-Assad step down, extending participation in an interim administration to the opposition and extending the mandate of an observer mission.
The League's proposal was welcomed by European Union foreign ministers meeting in Brussels, who approved new sanctions on 22 people and eight institutions.
The US also praised the Arab League's move, calling it "really quite remarkable."
"The Arab League has now joined the United States, the European Union, other countries around the world, in saying that it is now time for Assad to step aside and allow a peaceful political transition to go forward," State Department spokeswoman Victoria Nuland said.
"They made a concrete proposal, in line with the leadership that they have been showing on the Syria issue for many weeks now, about how this could happen."
"Regrettably, Assad rejected it, almost before the ink was dry. And, you know, this just speaks again to the fact that he's thinking about himself and his cronies, not about his people," Nuland added.
The individuals and companies will not be identified until the sanctions are published in the EU's official journal. "The Arab League plan ... seems a reasonable one, but unfortunately it has been rejected by the Syrian regime and that's regrettable," Italian Foreign Minister Giulio Terzi di Sant'Agata told reporters in Brussels.
German Foreign Minister Guido Westerwelle said: "I hope that this latest decision in the Arab League will convince some partners in the Security Council in New York ... that it is necessary to act."
It was not officially announced whether Syria had agreed to extend the Arab mission for an extra month, but a source close to the Syrian regime told dpa that "Damascus is keen to extend the mission."
In Cairo, the head of the monitoring mission, Sudanese General Mohammed al-Dabi, defended his widely-criticized mission and said that violence had decreased since the deployment of the observers, on December 26.
Al-Dabi added that "the mission was designed not to bring an immediate end to violence but to investigate and observe the situation on the ground."
He went on to say that his team had been able to persuade Damascus to remove tanks from neighbourhoods and to reduce the number of military and security teams deployed near demonstrations.
The opposition lashed out at the mission and described al-Dabi's comments "as lies and baseless."
"How can he say such a thing, when each day between 50 and 100 people are getting killed by this brutal regime," opposition figure Sheikh Anas Airout told dpa by phone from Turkey.
"This general is only sitting with the leaders of the regime and did not see what is going on the ground," Airout said.
Earlier Monday, opposition activists described the Arab League plan to transfer power in the country, as "unattainable" and said it gave al-Assad's government more time to kill more people.
Violence in the country continued, with activists reporting that more than 11 people had died in violence across Syria on Monday.
Five people were killed and 13 wounded when government forces and defectors clashed in the central province of Homs, according to the Syrian Observatory for Human Rights.
Six people were shot by security forces in an area near the neighbourhood of Baba Amr in Homs, they added.
SANA reported that "terrorists' gunfire" had killed seven people in cities across the country.
Syria has repeatedly blamed the unrest on "armed terrorist gangs" allegedly financed by Arab and western countries.