Thapa was recommended to the post by the erstwhile Khil Raj Regmi government in September last year. His name was endorsed by the 35th Saarc Council of Ministers held in the Maldives on February 20. The Saarc secretary general is picked from the member states on alphabetic order.

"My priority would be to implement at the earliest various regional and sub-regional projects that the member states had agreed to implement in the past," said Thapa, who is the second Nepali after Yadav Kanta Silwal to assume the post. Silwal held the top post of the regional body from January 1994 to December 1995.

Thapa entered the administrative service in 1983 at the Ministry of Law before joining the foreign service in 1999. He had served in various capacities in Nepali missions overseas, including Nepal's Ambassador to the UAE, Deputy Chief of Mission in Nepal's Permanent Mission in New York.