Syrian President Bashar al-Assad has blamed a foreign conspiracy for trying to destabilise Syria, as a mass uprising against his rule continues.
The "external conspiracy is clear to everybody", Mr Assad said in his first public remarks in months.
He said elections could be held later this year but "terrorism", he added, would be met with an "iron fist".
Meanwhile the Arab League said it held the government "totally responsible" for attacks against its observers.
In a statement issued on Tuesday, Arab League chief Nabil al-Arabi denounced "irresponsible action and acts of violence against the league's observers" in Syria.
Mr Arabi said some monitors had been wounded in attacks by both pro-regime elements and by opposition supporters.
Earlier, Kuwait's state news agency said two Kuwaiti members of the mission had been slightly injured on Monday in the city of Latakia by "unidentified protesters".
They were discharged from hospital and have now returned to their duties, Kuna news agency said.
'No order to fire'
President Assad's speech, broadcast live from Damascus University, was his third televised address since protests against his rule began in March, and lasted nearly two hours.
"Regional and international sides have tried to destabilise the country," he said.
"Our priority now is to regain the security in which we basked in for decades, and this can only be achieved by hitting the terrorists with an iron fist.
"We will not be lenient with those who work with outsiders against the country."
BBC world affairs correspondent Nick Childs says the speech was a riposte to those who are asking questions about the pressure under which Mr Assad is operating.
It was a message that there will be no concessions and its main theme was that nothing is going to change as far as the Syrian response is concerned, our correspondent says.
Syrian authorities say they are fighting armed groups, and that about 2,000 members of the security forces have been killed so far.
In recent months, army deserters have joined the opposition and targeted government forces.
A team of 165 monitors from the Arab League has been in Syria since December to monitor implementation of a peace plan that calls for an end to all violence, the removal of heavy weapons from cities and the release of all political prisoners.
Opposition groups have accused the Arab League mission of serving to cover up the crackdown on the protests, which has continued despite the presence of the observers.
Mr Assad said that there were no orders for security forces to fire on protesters.
"There is no order from any level about opening fire on any citizen. According to the law, nobody should open fire - only in self-defence or during a clash with an armed person."
Reacting to the speech, the head of the opposition Syrian National Council, Burhan Ghalioun, said Mr Assad's emphasis on restoring order "means he is backing away from his own pledge to the Arab League plan".
Mr Ghalioun said the anti-terrorist measures announced by Mr Assad "undercut any Arab or non-Arab initiative to find a political solution to the crisis".
The Local Co-ordination Committees, a network of anti-government activists, said 35 protesters had been killed on Tuesday, including 17 in the eastern city of Deir al-Zour.
The UN says 400 people have been killed by security forces since the start of the observer mission. Last month the UN put the death toll since March at 5,000.
'No snap reforms'
In his speech, Mr Assad lashed out at the Arab League, which suspended Syria in November and imposed sanctions, saying: "We were surprised Arabs did not stand with Syria".
He said Arab countries that opposed Syria were under outside pressure, which was undermining their sovereignty.
But, he added, Syria would not "close its doors" to an Arab solution as long as "it respects Syria's sovereignty".
There were no obstacles to a multi-party system, he said, adding that it was a question of time.
Mr Assad said he welcomed the idea of expanding the government to include "all political forces".
A referendum on a new constitution could be held in March, he said, paving the way for elections in May or June.
Syria is ruled by the Baath party, dominated by President Assad's family and the minority Alawite sect, an offshoot of Shia Islam.
He took power in 2000 after the death of his father Hafez al-Assad, who ruled Syria for 40 years.
"I rule with the will of the people," he said. "If I give up power, I will do so with the will of the people too."