SEOUL -- South Korea's main opposition Democratic Party (DP) on Monday urged the presidential office to immediately demand "clear information" from Washington on media reports about alleged attempts by the United States to eavesdrop on the South Korean government.

Rep. Park Hong-keun, floor leader of the DP, was quoted by Yonhap news agency as saying that "if the report is true, it would be an action that can never be acceptable between allies of 70 years, and an infringement of sovereignty and diplomatic foul play that breaks the bilateral trust head-on."

Park requested the National Assembly to immediately convene meetings of its foreign affairs, intelligence and defense committees to discuss the matter.

Lee Jae-myung, chief of the DP, said that "while it is absurd that a nation's presidential office is penetrated by eavesdropping, it is also difficult to accept eavesdropping on the offices of an ally's presidential office from a common sense point of view."

Lee said the DP will sternly respond to the issue while verifying details objectively.

South Korea would have necessary consultations with the United States over the "raised issues" on the US intelligence agency eavesdropping on the South Korean government, according to Yonhap, citing the presidential office.

An unidentified South Korean presidential official was quoted by Yonhap as saying on Sunday that it would consider countermeasures while reviewing past precedents and cases of other countries.