The setback is the latest to hit an intermittent peace process that aims to put an end to a more than three-decade conflict between Yerevan and Baku.

Both Armenian Prime Minister Nikol Pashinyan and Azerbaijani President Ilham Aliyev have been attending a summit of the European Political Community at Blenheim Palace near Oxford in England.

Hikmet Hajiyev, a foreign policy adviser to Aliyev, said that Armenia had refused a proposal for the two leaders to take part in a British-mediated meeting.

“We regard Pashinyan’s refusal to meet in London as its intention to retreat from the peace agenda,” said Hajiyev.

In response, Armenia’s foreign ministry issued a statement claiming that Yerevan had offered Azerbaijan a bilateral meeting in the U.K., but Baku had declined the invitation. The Armenian ministry said the offer remained open.

The most recent talks between Pashinyan and Aliyev took place in Berlin in February, mediated by German Chancellor Olaf Scholz.

Tensions over Nagorno-Karabakh

Both nations have expressed a desire to sign a peace treaty to resolve the conflict over Nagorno-Karabakh, a region that enjoyed de facto independence from Azerbaijan for over three decades until a rapid Azerbaijani offensive in September 2023 reclaimed the territory, causing approximately 100,000 ethnic Armenians to flee.

Since then, Armenia and Azerbaijan have been engaged in talks focused on demarcating their 1,000 km (625 mile) shared border, which remains closed and heavily militarized.

In May, Armenia returned to Baku four deserted Azerbaijani villages it had controlled since the early 1990s.

Azerbaijan, significantly larger in population than Armenia, also demands that Armenia amends its constitution to remove any indirect reference to Karabakh’s independence as part of the peace negotiations.