(CNN) -- Jennifer Lopez sang "Happy Birthday, Mr. President" on Saturday to a leader who has been characterized as one of the most repressive in the world.
"We wish you the very, very, happiest birthday," Lopez said to Turkmenistan President Gurbanguly Berdymukhamedov, and then she sang to him at a huge celebration at a resort in the central Asian country.
The singer's spokesman told CNN Sunday that "had there been knowledge of human right issues of any kind, Jennifer would not have attended."
Human Rights Watch, in a report to the U.N. Human Rights Committee, recently called Turkmenistan "a country marked by extraordinary levels of repression."
"Widely recognized as one of the most repressive in the world, the Turkmen government exercises total control of public life," the report said.
Lopez spokesman Mark Young said she "and several other artists were invited and performed at a private corporate event for the China National Petroleum Corporation that was presented to their local executives in Turkmenistan."
The event was not sponsored by the government and not political, he said.
"The China National Petroleum Corporation made a last-minute 'birthday greeting' request prior to Jennifer taking the stage," he said.
"This was not stipulated in her contract, but she graciously obliged the China National Petroleum Corporation request."
Once part of the Soviet Union until late 1991, Turkmenistan has abundant gas and oil resources. The CIA Factbook says the leadership uses its "gas and cotton export revenues to sustain its inefficient and highly corrupt economy." The country borders Afghanistan and Iran.
Berdymukhamedov has been chief of state and head of government since February 2007, the CIA Factbook says.
CNN's Denise Quan contributed to this report.