The leaders of Azerbaijan and Armenia will resume peace talks in Brussels this weekend, according to officials, as western allies are stepping up mediation efforts between the conflict-wracked neighbours following a recent uptick in fighting over their disputed border.

European Council president Charles Michel will host a meeting on Sunday between Azerbaijan’s president Ilham Aliyev and Armenia’s prime minister Nikol Pashinyan, three officials with knowledge of the preparations told the Financial Times.

It will be the first time the two leaders have met in person since talks in Munich in February and comes after the two countries’ foreign ministers held extensive discussions in Washington last week. US secretary of state Antony Blinken said those talks “made tangible progress on a durable peace agreement” and that he believed “an agreement [is] within sight, within reach”.

Hundreds of troops have been killed in sporadic clashes since a full-scale war in 2020 ended in an unstable ceasefire. Diplomatic efforts led by the EU and US on one side, and Russia on the other, have since then sought to broker a longstanding peace deal without success.

The two former Soviet republics have fought for control of the territory of Nagorno-Karabakh since the collapse of the USSR. The majority-Armenian region was previously controlled by Armenia before being largely captured by Azerbaijan in 2020.

The Brussels meeting is an “important sign of progress”, one of the three officials said on condition of anonymity as it is not yet public, adding that the EU and US efforts were “mutually reinforcing” and “complementary two-track processes”.

There are also plans for the three leaders to hold another meeting on June 1 with German chancellor Olaf Scholz and French president Emmanuel Macron on the sidelines of the European Political Community summit in Moldova, two of the officials said.

Spokespeople for Michel and Aliyev declined to comment. A spokesperson for Pashinyan did not respond to a request for comment.

“Azerbaijan feels quite comfortable with the Charles Michel mission because [the] EU doesn’t have a hidden agenda,” said Hikmet Hajiyev, Aliyev’s foreign policy adviser. He added that the EU process had developed “key concepts” for the negotiations and their structure.

The talks are likely to focus on Azerbaijan’s recent decision to install a checkpoint on the Lachin corridor, the only road access from Armenia to Nagorno-Karabakh. They will also feature discussions on border demarcation, prisoner exchanges and efforts to remove thousands of mines that litter the enclave.

Yerevan says Baku is using the checkpoint to strangle critical supplies of food and medicine to Nagorno-Karabakh, while Baku says it is necessary to prevent weapons being smuggled into the territory.

“Regulation of its own territory is normal for every country,” said Hajiyev. “The road is open, but the road is closed for illicit trafficking.”

The EU-led effort is also a test of its clout in its wider neighbourhood and a challenge to Moscow’s historic influence. Russia has about 2,000 troops stationed in Nagorno-Karabakh as peacekeepers after brokering the 2020 ceasefire.

Hajiyev said Baku was “flexible” about meeting in Moscow, Washington or Brussels, noting that the process should be more “inclusive” in order to yield results.

“Russia can effectively contribute to the peace-building process in the region,” said Hajiyev. “But it’s also true that Russia is very much preoccupied with the war in Ukraine.”