Vietnam has virtually deported a North Korean diplomat included on a list of individuals blacklisted by the U.N. Security Council in a March sanctions resolution, political sources said Wednesday.

The measure marked Hanoi's first implementation of the council's new sanctions in response to the North's fourth nuclear test in January and its subsequent rocket launch using ballistic missile technology.

Choi Song-il, vice chief of the Hanoi branch of the North's Tanchon Commercial Bank and one of the 16 individuals on the list, returned to North Korea on a flight Saturday, the sources said. He had already been blacklisted by the United States in December last year.

Under the resolution, the members of the world body are required to freeze overseas assets of organizations and individuals subject to the new sanctions, deport them and place them under a travel ban.

It is believed that the Vietnamese government requested that Choi leave the country in consideration of its ties with the North rather than deport him, and Choi accepted the request, the sources said.

Kim Jung-jong, the chief of the Hanoi branch who was also included on the U.N. blacklist, returned home about one month ahead of the adoption of the sanctions resolution, escaping deportation from Vietnam.

The branch is suspected of having been involved in laundering and transmitting money earned from the North's deals of arms sold overseas, since it was relocated from Myanmar in July 2012. 

The U.S. believes that the bank was connected to Korea Mining Development Trading Corp. , which was also blacklisted by the U.N. sanctions committee for their suspected involvement in nuclear and missile development.

The office of the bank's Hanoi branch is believed to be located in the North Korean Embassy in Hanoi.

South Korea has been working on ways to place the replacement of the branch under the sanctions since he came to the post in January. (Yonhap)