U.S. Senator John Kerry has demanded North Korea immediately release two American journalists it detained over two months ago.

Laura Ling and Euna Lee, two reporters of San Francisco-based Current TV, were detained by North Korea on March 17th while filming a documentary along the North's border with China.

Kerry made the release demand during a Senate hearing on Thursday for U.S. special envoy on North Korea Stephen Bosworth.

In response, Bosworth said Washington is pursuing every possible approach to persuade the North to free the two women.

The senator said the release of the two journalists should not be related to disputes over the North's May 25th nuclear test.

Kerry is the chairman of the Senate Foreign Relations Committee and was the Democratic Party’s presidential candidate in the 2004 presidential race.