President Moon Jae-in picked special envoys to the United States, China, Japan and Russia, a source said Sunday, as he strives to build closer ties with the four major powers amid persistent military threats from a provocative North Korea.

The source said that Moon picked Hong Seok-hyun, a former chairman and CEO of the JoongAng Media Network, and former Prime Minister Lee Hae-chan as special envoys to the US and China, respectively.

Rep. Moon Hee-sang and Rep. Song Young-gil of the ruling Democratic Party were selected as special envoys to Japan and Russia, respectively, according to the source who requested anonymity.

Cho Yoon-je, a professor at Seoul's Sogang University, is said to have been picked to cover the European Union and Germany.

These envoys are expected to deliver to the foreign governments a handwritten letter from Moon underscoring his resolve to strengthen diplomatic cooperation with them. They are also likely to explain the new Seoul government's policy vision, the source said.

Hong, who served as Seoul's ambassador to the US in 2005, is known to have wide personal connections in Washington.

His delegation is said to include DP Rep. Hwang Hee, Poongsan Group Chairman Ryu Jin, former Ambassador to Thailand Chung Hae-moon and Park Sun-won, former presidential secretary for diplomatic and security strategy.

Former Prime Minister Lee already served as a special envoy to China during the former Roh Moo-hyun government in 2003. His delegation is said to include DP Reps. Shim Jae-kwon and Kim Tae-nyeon, former career diplomat Shin Bong-kil and Suh Choo-suk, a former senior presidential secretary for foreign affairs.

Moon is also noted for his wide personal network in Japan that he built while leading the Korea-Japan Parliamentarians' Union from 2004-2008.

Moon's delegation is said to consist of DP Reps. Won Hye-young and Yun Ho-jung, Kim Sung-bae, a senior researcher at the Institute for National Security Strategy, and Suh Hyung-won, who served as a diplomatic minister in Japan.

Song is a vice chief of the diplomatic council consisting of South Korean and Russian lawmakers. He is also noted for his deep ties with Russia that he has developed while doing a series of cooperative projects with Russia during his term as Incheon mayor from 2010-2014.

His delegation is said to include DP Reps. Jung Jae-ho and Park Ju-min, former Ambassador to Belarus Lee Youn-soo, and Cho Sung-ryeol, a researcher at the Institute for National Security Strategy. (Yonhap)