New York, Feb 7 (IANS): The Commonwealth should shift the venue of its November summit from Sri Lanka unless Colombo makes prompt, measurable and meaningful progress on human rights, Human Rights Watch said Thursday.

The rights body made the appeal in a public letter to Commonwealth heads of government. Commonwealth Secretary-General Kamalesh Sharma is set to visit Sri Lanka Feb 10 to discuss the upcoming meeting.

The Sri Lankan government under President Mahinda Rajapaksa "has taken no meaningful steps to address serious abuses by government forces in the final months of the armed conflict" against the Tamil Tigers, it said.

It quoted the UN as estimating that up to 40,000 civilians were killed in the final stages of the war that destroyed the Liberation Tigers of Tamil Eelam (LTTE) in May 2009.

Since then, the government had been responsible for a worsening human rights situation that includes clampdown on basic freedoms and attacks as well as threats against civil society, it said.

There were also actions against the judiciary and other institutions, the open letter said.

"The Sri Lankan government's blatant disregard for the Commonwealth's principles of human rights and democratic reform makes it a poor host for this important event," said Brad Adams, Asia director at Human Rights Watch.