"For the moment, there is no other legal basis that would help a resolution. There is no alternative to these trilateral documents," Kremlin spokesman Dmitry Peskov told reporters.

Initiatives to lower tensions in the region "are possible above all on the basis of the trilateral documents signed with Russia," he said.

The United States this week is hosting negotiations between Armenia and Azerbaijan, seeking to quell recent tension over the disputed enclave of Nagorno-Karabakh.

The two sides have gone to war twice, in 1990 and 2020, leaving tens of thousands dead and clashes regularly erupt over the territory, an Armenian-majority region inside Azerbaijan.

Tensions have spiked again in recent days after Azerbaijan announced it had set up a checkpoint on the Lachin corridor, the only land link between Armenia and Nagorno-Karabakh, sparking an angry response from Yerevan.

Armenia views the move as a violation of the cease-fire negotiated between the two sides.

Moscow brokered a ceasefire between Yerevan and Baku after the latest bout of fighting in 2020 and posted peacekeepers along the Lachin corridor.

With Russia bogged down in Ukraine and unwilling to strain ties with Azerbaijan's key ally Turkey, the United States and European Union have sought to steer a thaw in ties.