Seoul, Oct 29 : The US is reviewing the possibility of declaring a formal end to the Korean War from various angles, a top American diplomat has said. Mark Lambert, Deputy Assistant Secretary of State for Korea and Japan, made the remark in a meeting with Lee Seok-hyun, vice chairman of South Korea's National Unification Advisory Council, Yonhap News Agency reported on Friday. The Council offers policy recommendations to the South Korean president. Lambert's remark comes after White House National Security Advisor Jake Sullivan noted possible differences between South Korea and the US over when a declaration of the war's end could be or should be made. South Korean President Moon Jae-in proposed declaring a formal end to the 1950-53 war as a catalyst to resume dialogue with the North. Pyongyang has stayed away from denuclearization talks since 2019. It also remains unresponsive to numerous overtures for dialogue from US President Joe Biden's administration. Lee said US outreach to the reclusive North so far included a dialogue proposal through email. "The US continues to propose holding dialogue, even sending an email to North Korea in recent days, but North Korea is not responding," the South Korean official said , adding the North appears to be uninterested in talking directly with the US at least for now. Meanwhile, a group of US lawmakers is expected to send a letter to President Biden next week to urge diplomatic engagement with North Korea and also support for the Seoul-proposed end of war declaration, an informed source said. /IANS