The talks sponsored by regime allies Russia and Iran and rebel backer Turkey will begin Monday in Astana and are expected to last less than a week.
Details on the format of the talks remain murky, but Assad told Japanese television channel TBS that a stop to fighting would be the priority.
"I believe that they will focus, in the beginning, and will prioritise, as we see it, reaching a ceasefire," Assad said, according to excerpts released by his office.
"This will be to protect people's lives and allow humanitarian aid to reach various areas in Syria," he said.
Moscow and Ankara brokered a truce between Assad's forces and rebel fighters last month, but clashes have escalated across the country in recent weeks.
And the UN's envoy on Syria, Staffan de Mistura, last week lamented that the truce had not brought any additional access of humanitarian aid deliveries.
Repeated attempts by world powers to end Syria's war, which erupted nearly six years ago with widespread anti-Assad demonstrations, have failed to bear fruit.
Last year, the United States and Russia worked together to put a temporary truce in place and sponsored several rounds of talks in Geneva, but they did not secure a political solution.
In late 2016, a new partnership between Moscow and Ankara emerged, despite their backing for opposite sides in the conflict, and the Astana talks will be the first test of their joint efforts.
The two powers have said US President-elect Donald Trump's administration should attend the talks, but Iranian officials have voiced strong objections to Washington's presence.
Assad proposes reconciliation
Assad said an agreement at Astana would "allow these (rebel) groups to join the reconciliation deals in Syria".
Damascus has reached a series of local deals under which rebels evacuate areas in exchange for an end to bombardment or sieges.
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Assad said if a similar deal was struck in Astana, opposition fighters would "lay down their arms and receive an amnesty from the government. This is the only thing we can expect at this time."
Such deals have been fiercely criticised by rebel groups as a deliberate strategy of displacement.
Several major rebel groups announced on Monday that they would attend the Astana talks to discuss the fragile truce and improved humanitarian access.
They announced a delegation of eight representatives, led by Mohammad Alloush of the Jaish al-Islam (Army of Islam) rebel faction.
But the powerful Ahrar al-Sham faction, which counts thousands of fighters in central and northern Syria, said Wednesday it would sit out the talks.
It blamed "the lack of implementation of the ceasefire" and a fierce regime offensive on Wadi Barada, an area 15 kilometres (10 miles) northwest of Damascus.
The area is the capital's main source of water, and the fighting has left some 5.5 million people in Damascus and its suburbs facing water shortages since late December.
Key spring surrounded
Syrian government forces and allied militia groups surrounded Wadi Barada on Thursday, where around 20,000 people live, a monitor said.
The Syrian Observatory for Human Rights said regime loyalists cut the route between Wadi Barada and adjacent rebel-held territory in Qalamun.
The regime is seeking to gain full control over the area -- including the key Ain al-Fijeh spring -- to restore running water to the capital.
In addition to devastating infrastructure, Syria's conflict has killed more than 310,000 people and forced millions to flee their homes.
On Wednesday, the newly-elected chief of the United Nations said the war was "too dangerous" to go unresolved.
Antonio Guterres, who took charge of the world body on January 1, voiced hope that talks in Astana "can lead towards a consolidation of the ceasefire and a freeze in the conflict".
Success in Astana "can help create the conditions for a political process that should resume in Geneva in February that can lead to concrete results", he added.