Ukraine, trying to fend off Russia’s invasion, signed the instrument of accession to the Treaty of Amity and Cooperation in South-east Asia on Thursday.
A total of 50 parties have now joined ASEAN’s peace pact, which was originally signed among ASEAN member states in 1976 to promote peace and cooperation within the region.
It is a prerequisite for countries that want to establish formal partnerships with ASEAN.
China, India, the United States, the European Union and Russia are among its other signatories.
The treaty’s key principles are mutual respect for independence and territorial integrity, the settlement of disputes by peaceful means, and the renunciation of the threat or the use of force.
Ukraine’s accession to the treaty was seen as a sign of support for Ukraine, despite ASEAN members’ differing stances on the Russian invasion.
While Singapore has imposed sanctions on Russia, other ASEAN member states like Laos and Vietnam, which rely on Russia for military equipment, have avoided directly criticizing Moscow.
Thailand, Vietnam and Laos abstained from an October vote at the United Nations General Assembly that condemned Russia for trying to annex parts of Ukraine.
Cambodia, which chairs ASEAN this year, co-sponsored the resolution.
Ukrainian Foreign Minister Dmytro Kuleba, who arrived in Phnom Penh on Tuesday evening, signed the treaty on behalf of his country.
On Wednesday, he held a meeting with Cambodian Prime Minister Hun Sen.
“We focused on bilateral cooperation and global food security,” Kuleba tweeted on Wednesday.
The in-person meeting followed a phone call between Hun Sen and Ukrainian President Volodymyr Zelensky on Nov 1, when both countries agreed to appoint ambassadors to boost diplomatic ties.