COLOMBO: Sri Lanka is still in talks with the United States on a status-of-forces agreement (SOFA) for visiting US military personnel, the prime minister said, disregarding a warning by the president that it would undermine sovereignty.

President Maithripala Sirisena and Prime Minister Ranil Wickremesinghe have been at loggerheads since last year and their political differences have now stretched to security ties with the United States.

Wickremesinghe told parliament on Wednesday that the proposed SOFA was not a military pact but only an agreement establishing the rights and privileges that US military personnel would enjoy if they were in the country.

"The SOFA is a peacetime document, and does not address the rules of war, laws of armed conflict, or laws of the sea. It does not authorise specific exercises, activities, or missions," he said.

He said it only established the framework for US military personnel operations, and that while the discussions were under way he would not support any agreement that threatens Sri Lanka's sovereignty.

Sri Lanka sits near one of the world's busiest shipping routes in the Indian Ocean and over the last several years China has become a major investor, building ports and highways.

India, which is just next door, is starting to push back against China's growing influence and so are the United States and Japan, experts say.

Sirisena, however, said he would not sign any military cooperation deals that are "unsuitable for the country".

US Ambassador Alaina B. Teplitz, trying to assuage concerns over US involvement in the tiny island, said last week that there were no plans to set up a military base.

"I think what we are to be focusing on here in our relationship are those common security interests both of our countries have," Teplitz said state-owned TV channel Rupavahini.

"What we would like to see is very strong, capable, sovereign Sri Lanka, well able to defend its shores and control its waters, keep the air space open so that all nations can transit and everybody is following the rules and norms for the international order," she said.