Ustubs began his position in Canada in September of 2017. He previously worked in the office of EU High Representative for Foreign Affairs and Security Policy Federica Mogherini as senior advisor on the Americas. Ustubs was also the deputy head of office for EU Commissioner for Development Andris Piebalgs.
Ustubs has worked in the EU External Action Service, including as the Director for Western and Central Africa.
Ustubs is the former Latvian ambassador to the EU Council Political and Security Committee in Brussels and the political director at the Ministry of Foreign Affairs. He began working in the Latvian diplomatic service in 1993.