"We all have to discuss and find ways to continue the peace process," Mahinda Rajapakse, the president, told the party leaders on Monday, referring to the peace talks between Colombo and the Tamil rebels.
Those invited to the discussion with the president ranged from Buddhist monks to Marxists.
It was the first meeting of all the main parties since government representatives met rebel leaders in Geneva last month, when they agreed to try to stop the violence and to meet again next month.
Truce monitors, however, fear that renewed violence - with three deaths in past three days - could put the peace talks in jeopardy.
"We all have to discuss and find ways to continue the peace process"
Sri Lankan president
Rajapakse has been criticised by two of his close allies - the Marxist People's Liberation Front and the radical Buddhist group Jathika Hela Urumaya - as well as by the main opposition United National Party over the way the peace talks are being conducted.
The Marxists and the monks' party oppose any concessions for the rebels, who began fighting in 1983 to create a separate homeland for the island's 3.2 million Tamil minority.
The support of the two allies - which together have 50 seats in the 225-member legislature - is crucial for Rajapakse's minority government.
The opposition UNP, which previously said it would back the government's peace efforts, is now demanding more transparency. It was during an earlier UNP government that the Norwegian-brokered ceasefire was signed in 2002, ending nearly 20 years of fighting that killed 65,000 people.
Recent violence has killed at least 150 people, including 81 government security officers, and led to an increase in tensions and concerns over the stability of the ceasefire.