[6] In the 1960s he was sent by the Oblates as the first Laotian to study philosophy and theology at the Voluntas Dei seminary in the Diocese of Edmundston, New Brunswick, Canada.

He was ordained a priest in a hurried ceremony in a refugee camp[3] on 5 November 1972 for the Apostolic Vicariate of Vientiane, Laos.

[7] He worked as a priest in the Vicariate of Vientiane for more than 25 years, more than a decade of that time in rural areas,[6] and became its vicar general.

On 30 October 2000, Pope John Paul II appointed him Vicar Apostolic of Paksé and titular bishop of Aquae Novae in Proconsulari.

"[1] His other principal charges as a bishop in Laos have been providing formation for Laotian priests, since the government does not allow foreign missionaries to work there,[5] and planning for his own successor.

[16] Francis made him a member of the Dicastery for Promoting Integral Human Development on 23 December 2017[17] and of the Pontifical Council for Interreligious Dialogue on 8 July 2020.