US Secretary of State Antony Blinken on Monday asked Azerbaijan President Ilham Aliyev to redouble efforts in bilateral peace discussions with Armenia and urged an immediate reopening of the Lachin corridor to commercial traffic, the State Department said.

Tensions have spiraled between Armenia and Azerbaijan over the blockade of the only road giving direct access to the disputed Nagorno-Karabakh region from Armenia in recent weeks.

Blinken’s talks with Aliyev on Monday followed the secretary of state’s call with Armenian Prime Minister Nikol Pashinyan on Wednesday, when they discussed steps to restart bilateral talks with Azerbaijan.

“He (Blinken) underscored that the risk of a humanitarian crisis in the Lachin corridor undermined prospects for peace between Armenia and Azerbaijan,” the State Department said in a statement on Monday.

Blinken also raised human rights concerns in Azerbaijan when he spoke to its president, the State Department added.

Last week, Russia also told Azerbaijan that the key road leading into the disputed region of Nagorno-Karabakh must be quickly cleared of protesters, but Baku remained unmoved.

Nagorno-Karabakh is internationally recognized as part of Azerbaijan but home to a mainly Armenian population. The issue is becoming a major irritant for Russia, which wants to maintain good relations with both Azerbaijan and Armenia, two small former Soviet states in the Caucasus region.

Azerbaijanis who say they are environmental activists have blockaded the road for weeks in what they say is a dispute over illegal Armenian mining. Yerevan says they are government-backed agitators. The impasse is being seen as a test of Russia’s ability to calm hostilities in its backyard.

Russian Foreign Minister Sergei Lavrov said last week Russia was ready to deploy troops to the Armenia-Azerbaijan border to quell tensions between the two countries, but Yerevan’s hardline position had so far prevented it.