The leaders of both countries had agreed in Brussels on Sunday to work on a peace plan, despite protests in Armenia fuelled by opposition claims that Prime Minister Nikol Pashinyan was making too many concessions.
The border meeting, confirmed by both governments in near-identical statements, brought together border delimitation commissions from both sides, each headed by a deputy prime minister.
The delegations agreed to hold a second meeting in Moscow and a third in Brussels.
The dispute over Nagorno-Karabakh, a mountainous territory inside Azerbaijan controlled since the 1990s by ethnic Armenians supported by Yerevan, flared in 2020 into a six-week war in which Azeri troops regained swathes of territory.
Russia brokered a ceasefire, and European Council President Charles Michel has also supported reconciliation efforts, hosting a meeting with both Pashinyan and Azeri President Ilham Aliyev in Brussels last Sunday.
Pashinyan has faced a series of protests at home in recent weeks since he said the international community wanted Armenia to "lower the bar" on ethnic Armenian claims to Nagorno-Karabakh.
Michel said on Sunday that he would hold another trilateral meeting with Aliyev and Pashinyan by July or August.
(Writing by Kevin Liffey; Editing by Paul Simao)
