COLOMBO, Jan 9: The Sri Lankan government upped the stakes on Friday in a battle with the island's president that risks efforts to end 20 years of civil war, telling her to redo a ceasefire with Tamil guerillas or give up control of security.

Efforts to restart stalled peace talks with the Tamils have been frozen since November when President Chandrika Kumaratunga seized the defence, interior and media ministries, although the Norwegian-brokered truce has continued to hold.

"If her excellency the president insists on retaining the portfolios, there has to be a change with regard to the substance of the ceasefire agreement," cabinet spokesman G.L. Peiris told a news conference.

"We cannot guarantee a ceasefire in which we have no control over the armed forces," he said. Analysts have said that if Prime Minister Ranil Wickremesinghe and Kumaratunga - who are elected separately and are from rival parties - cannot find a way to work together there could be snap parliamentary elections.

Peiris stressed the government would not pull out of the agreement, which has given the island its best chance yet to end the war that killed 64,000, but said Wickremesinghe could not be responsible for its implementation without control over security.

Kumaratunga said she took over the ministries because Wickremesinghe was compromising security by conceding too much to the Tigers. He denies that, and has said he cannot continue to lead the peace process unless he also controls defence.

Peiris said the government would also bring a motion to amend election laws so upcoming provincial council elections are held on one day, instead of staggered over several months.

It is thought Kumaratunga might use the provincial polls to gauge her popular support. As the two ratchet up pressure on each other, international calls to end the impasse are also increasing, with US Secretary of State Colin Powell last week urging them to resolve their differences and Japanese envoy Yasushi Akashi expected on January 19.

Japan is Sri Lanka's biggest aid donor, and Peiris said Akashi would bring together donor countries and multilateral organisations to review aid strategy in light of the crisis.

"The outcome is not going to be positive. Things have come to a halt and that will definitely affect the situation with regard to the resources pledged in Tokyo," Peiris warned, referring to $4.5 billion pledged in June, conditional on progress in the peace process.-Reuters