Bashar al-Assad, the Syrian president, said his country would not bow to "intensifying pressure or foreign plots", in a statement taken as a rejection of an offer of talks and an indication that the war will continue.
The opposition leader Moaz al-Khatib earlier said he had received "no clear response" from Damascus over his offer to hold talks with Farouq al-Sharaa, the vice-president, to find a political way out of civil war.
Yesterday, Mr Assad seemed to reject talks directly in a state media report of a meeting with officials from Jordan. "Syria will remain the beating heart of the Arab world and will not give up its principles despite the intensifying pressure and diversifying plots not only targeting Syria, but all Arabs," he said.
Mr Khatib surprised both the regime and members of the opposition by extending the offer of direct talks on the condition that the discussions centred on finding a new leader.
Last week, Omran al-Zohbi, the information minister, said the government would not open discussions with such conditions in place. Mr Assad's speech is likely to be read as a formal rejection of Mr Khatib's overture, and as further evidence that he has little intention of negotiating his departure.
Mr Khatib's manoeuvre was backed by the US and has some support from Iran, the Assad regime's long-standing ally, opposition sources suggested.
One Iranian diplomat suggested last week that the regime should hold out in the hope that after a further month's stand-off, Mr Khatib would propose talking to Mr Assad himself. Mr Khatib's move was criticised by many in the Syrian National Coalition and caused some prominent participants to freeze their membership.
"I will not participate in the coalition until it starts behaving like a group again, and not to the whims of one man, Mr Khatib," said Dr Kamal Labwani. "We signed laws at the beginning promising that we would not negotiate with the criminal regime."
In two years of war, more than 65,000 people have been killed, and the social bonds that kept the country's mixed sects living in peace are collapsing.
The regime's military losses are increasing. In what it called one of Mr Assad's "biggest setbacks", the Britain-based Syrian Observatory for Human Rights reported yesterday that Islamist fighters seized control of the Taqba dam, an electricity plant that once fed much of Aleppo's power. In Damascus, government forces brought up tanks to defend an area just east of the city centre, residents reported.
An explosion on the Syrian Turkish border yesterday killed at least 10 people and wounded dozens. A Syrian-registered car is believed to have been at the heart of the blast. (© Daily Telegraph, London)