In 1841 he was assigned to the project to establish a Belgian colony at Santo Tomás de Castilla in Guatemala.
[3] Between 1855 and 1859 t'Kint negotiated Belgium's first treaties of amity and commerce with Guatemala, Honduras, Nicaragua, Costa Rica and El Salvador.
[3] In December 1859 he was appointed Belgian consul general, chargé d'affaires and plenipotentiary to Mexico, signing a treaty of amity, commerce and navigation on 20 July 1861.
The first treaty of amity, commerce and navigation between China and Belgium was signed in Beijing on 2 November 1865, and in December t'Kint arrived in Yokohama as the first Belgian diplomat in Japan, where he concluded a treaty of amity, commerce and navigation that was signed in Edo on 1 August the following year.
[4] In December 1868 he was appointed Leopold II of Belgium's extraordinary envoy and minister plenipotentiary to both China and Japan.