The United States (US) called Wednesday for the reopening of the only road linking Armenia with the breakaway region of Nagorno-Karabakh.
It also called on both Armenia and Azerbaijan to continue dialogue on ending their long-running conflict over Karabakh.
Secretary of State Anthony Blinken spoke with Azerbaijan President Ilham Aliyev, the State Department said, one day after the country closed the so-called Lachin Corridor.
Blinken "underscored the need for free transit of commercial, humanitarian, and private vehicles through the Lachin corridor," the department said in a statement.
On Tuesday, Azerbaijan said it was shutting the road, accusing the Armenian branch of the Red Cross of smuggling.
Karabakh has been at the center of a decades-long territorial dispute between Azerbaijan and Armenia, which have fought two wars over the mountainous territory, mainly populated by Armenians.
Since December Armenia has been warning of the risk of a humanitarian crisis in the territory as food and medicine run short due to restrictions on use of the Lachin route.
Blinken also spoke with Armenian Prime Minister Nikol Pashinyan and expressed his support for peace talks between the two countries and the need for direct dialogue between them, the department said.
In late June Blinken met in Washington with his counterparts from Armenia and Azerbaijan and reported progress toward ending the dispute but no agreement.
More talks are scheduled for this month under mediation by the European Union.
