British Prime Minister David Cameron has arrived in Kazakhstan, becoming the first serving British leader to visit the Central Asian nation.

Human rights groups have criticized the trip, saying the government of President Nursultan Nazarbayev imprisons critics, restricts the media and limits freedom of expression.

Cameron, who hopes to sign lucrative business deals with oil- and gas-rich Kazakhstan, said "there's never anything off the table" in talks and promised he would raise human rights issues with Kazakh officials.

But he noted that "Kazakhstan is one of the rising economic powers in the world" and important to British business interests.

He said it was "high time" a British leader visited, according to the Press Association news agency.

Cameron flew to the Kazakh capital, Astana, on Sunday after visiting Afghanistan and Pakistan.