A pro-unification organization on Friday urged the US Congress not to hold a hearing on a South Korean law banning the sending of anti-North Korean leaflets, calling such a move a "clear infringement" on their country's sovereignty and interference in domestic affairs.

The North Korean Committee for the June 15 Joint Declaration, which was established to uphold the peace agreement from the first inter-Korean summit in 2000, made the appeal in a statement that the group said was co-signed by about 420 civic organizations.

The statement was sent to the US government and the foreign affairs committees of the Senate and the House of Representatives amid expectations that a hearing on the matter is likely to take place in Washington, according to the committee.

"The judicial, administrative and legislative branches of the Republic of Korea have played their respective roles to protect the lives and safety of the people in accordance with democratic procedures," the statement said. "Even if there is a shortfall, it is to be addressed by the people, the government and the National Assembly of Korea."

"It is a clear infringement of Korea's sovereignty and an interference in its domestic affairs to hold a hearing on the legislative acts," it added. "The US Congress and the government should immediately stop any undue interference in Korea's domestic matters and intervention in its sovereign action."

In December, the National Assembly, controlled by the ruling Democratic Party, passed the bill penalizing the flying of anti-Pyongyang propaganda leaflets into North Korea, saying that it is aimed at protecting the safety of people living in border towns from where leaflets are usually sent.

The ban came months after the North blew up a joint liaison office in protest, and critics have claimed that the legislation is tantamount to caving to Pyongyang's pressure.

US politicians and others have also said that the legislation could erode freedom of expression and block one crucial avenue for sending free world information into the reclusive country.

US House Rep. Chris Smith (R-NJ) earlier criticized the legislation as disregarding "fundamental civil liberties" and expressed an intent to hold a hearing on the issue.

On Wednesday, Park Sang-hak, a vocal North Korean defector group activist, left for the US to attend the planned hearing, though the date for the hearing has yet to be determined, his lawyer said. (Yonhap)