Addressing a gathering in the southwestern town of Matugama, about 75 km from here, he said, "They only talk about the last 30 days of the war (with the LTTE) when all that happened during 30 years is happily ignored.
"If one were to probe the last days of World War II, you could bring war crimes charges," Rajapaksa said, referring to efforts by the US to move the resolution at the UNHRC.
Rajapaksa's comments coincided with the arrival in Colombo of US Assistant Secretary of State for Central and South Asian Affairs Nisha Biswal for discussions on the rights situation.
During a similar visit earlier this month by another top American official, Stephen J Rapp, it was said that the US resolution would press for an investigation into the last phase of the campaign against the LTTE in 2009.
The US resolution is due to come up at the UNHRC session in March. Two previous resolutions backed by India, which were adopted by the Council, sought commitments from Sri Lanka on reconciliation and rights accountability.