Belgium’s King Philippe met Vietnamese leaders on Tuesday as the two countries signed deals to cooperate on areas including green hydrogen.

A large business, academic and political delegation is accompanying the king in the first visit to Vietnam by a Belgian monarch.

Vietnam’s President Luong Cuong said Philippe’s trip was a milestone in bilateral relations, according to Vietnamese state media.

He urged Belgium to ratify an investment protection agreement between Vietnam and the European Union, which was signed in 2019 but still needs to be ratified by a third of the EU’s 27 states, according to the EU Council website.