But they question the credibility of his efforts to come clean on the past and to stem what they say are ongoing rights violations.
"The human rights situation in Sri Lanka continues to deteriorate, despite some areas of limited progress," US envoy Paula Schriefer told the council as she presented the resolution.
She highlighted concern over sexual violence, enforced disappearances, extrajudicial killings, torture, violations of the rights to freedom of expression, association and peaceful assembly, and threats to judicial independence and the rule of law.
She also cited intimidation of and reprisals against human rights campaigners, lawyers and journalists, and attacks on minority groups, including Muslims, Christians, and Hindus.
Sri Lankan ambassador Aryasinha countered that such allegations were biased, and being driven by pro-Tiger activists around the world.
"Such biases and extreme ideologies ignore the ground realities, the legitimate aspirations of the Sri Lankan people,