Syrian President Bashar al-Assad has said the government needs more time to "win the battle" against rebel forces.
In an interview with pro-government al-Dunya TV, Mr Assad also dismissed as "unrealistic" the idea of creating humanitarian buffer zones within Syria.
Opposition activists say the army has launched offensives across the country to regain control of rebel-held areas.
Meanwhile, rebels claimed to have seized 10 missiles from the regime's arsenal near the capital, Damascus.
The rebels posted unverified footage on YouTube which purported to show a storage warehouse seized from troops.
Heavy shelling has been reported in several cities, including Damascus, Aleppo, and the north-western province of Idlib.
Officials told state media on Wednesday that soldiers had repelled a "terrorist attack" on the military air base in the northern town of Taftanaz, inflicting heavy losses.
The reports came after rebel fighters claimed they had destroyed several military helicopters using two captured tanks.
The claims could not be independently verified, but a video posted online by local activists purported to show the destroyed helicopters. Smoke could be seen rising from the airfield.
Security forces 'heroic'
In excerpts of his interview with al-Dunya, which was broadcast in full on Wednesday evening, Mr Assad said the Syrian government was "fighting a battle both regionally and internationally".
"It definitely needs time to bring it to a decisive end. But I can sum it up in one sentence: we're heading forward," he told al-Dunya. "The situation on the ground is better now, but the conclusion is not there yet. That needs some time."
The security forces were "doing a heroic job in every sense", he added.
"Everyone is worried about their country - that is normal. But [the rebels] will not be able to spread fear, they never will," he said. "I say to Syrians: destiny is in your hands, and not in the hands of others."
The president mocked senior government and military officials who have defected in recent months, saying their departure amounted to a "self-cleansing of the government firstly, and the country generally".
Responding to rumours about his whereabouts since a July bombing in Damascus killed four senior officials, he revealed that he was being interviewed from the presidential palace in the capital.
Mr Assad also addressed the proposal by Turkish Foreign Minister Ahmet Davutoglu to set up a United Nations-sanctioned "safe zone" inside Syria to shelter refugees and help distribute humanitarian aid.
"Talk of buffer zones firstly is not on the table and secondly it is an unrealistic idea by hostile countries and the enemies of Syria," he said.
"Do we go back because of the ignorance of some Turkish officials or do we focus on our relationship with the Turkish people, especially those people who have stood by us during the crisis and were not swayed by the media and material propaganda?"
French Foreign Minister Laurent Fabius admitted on Wednesday that creating a buffer zone would be impossible without imposing a no-fly zone deploying ground forces.
"We are thinking about this. It is very complicated. We cannot do it without the agreement of the Turks and other countries," he told France Inter radio.
"But what we want is for things to move forward, to make Bashar fall as quickly as possible and at the same time find humanitarian solutions."
The UN refugee agency warned on Tuesday that as many as 200,000 refugees could flee to Turkey to escape fighting in Syria - almost double the number Turkey has said it can take.
The UNHCR said 5,000 refugees were now arriving at the Turkish border every day, compared to about 500 earlier this month. There are already more than 74,000 in Turkey, and 128,000 in other countries.
There are also thought to be more than 1.2 million internally displaced people in Syria, and 2.5 million in need of humanitarian assistance.
In a separate development, activists said a rebel group known as the Gathering of Ansar al-Islam Battalions had seized 10 surface-to-surface missiles.
However it is not clear if guerilla fighters would be capable of deploying them, reports the BBC's Barbara Plett in Beirut.
Our correspondent says the warehouse is in a district known as Ghuta, which includes the eastern outer suburbs of Damascus, said to be home to some of the best organised armed opposition groups.
Source: BBC News