US Secretary of State Mike Pompeo on October 27 called on the leaders of Azerbaijan and Armenia to abide by a Nagorno-Karabakh conflict ceasefire which the previous day collapsed minutes after it went into effect.

Armenia and Azerbaijan exchanged blame for the collapse of the US-brokered ceasefire as the war, now in its second month, intensified, particularly near the border with Iran. October 27 also saw Iran announce that Seyed Abbas Araghchi, the Iranian deputy foreign minister for political affairs, would embark on a regional tour of at least four capitals—Baku, Yerevan, Moscow and Ankara and possibly others—in an attempt at helping to resolve the crisis. 

In phone calls with Armenian Prime Minister Nikol Pashinian and Azerbaijani President Ilham Aliyev, Pompeo "pressed the leaders to abide by their commitments to cease hostilities and pursue a diplomatic solution to the Nagorno-Karabakh conflict," the US State Department said. He also told the two leaders that "there is no military solution to this conflict," it added.

Fighting was reported along several parts of the front line on October 27. Heavy clashes were said to be taking place in the southern sector near the border with Iran.

Armenia said Azerbaijan was using drones and artillery to strike border guard positions along its internationally recognised border in the southeast near Iran, meaning Armenian forces had little choice but to strike back. Azerbaijan denied the claims and in turn accused Armenian forces of firing mortars at its positions in Zangilan, Khojavend, Fizuli, and Gubadli.

Armenian Defence Ministry official Artsrun Hovhannisian said in a news conference late on October 26 that ethnic Armenian forces had given up the settlement of Gubadli that lies south of the Nagorno-Karabakh enclave and is just seven kilometres from the Armenian border. He said it was given up "to avoid unnecessary losses," but the situation was "not critical."

Meanwhile, the head of Karabakh’s Armenia-backed defence forces, Lieutenant General Jalal Harutiunian, was replaced after reportedly being wounded in action.
Pashinian said the ceasefire had collapsed.

"I would like to state that the efforts of the international community, this time brokered by the United States, to establish a cease-fire, have failed. As a result of continuous shelling by Azerbaijan, civilians were killed and wounded in Artsakh [the Armenian name for Nagorno-Karabakh] today," he said on Twitter.

Two previous Russian-brokered ceasefires also collapsed soon after going into effect.

The US, France, and Russia—co-chairs of the Minsk Group of the Organization for Security and Cooperation in Europe (OSCE), a mediation group—said its foreign ministers would meet on October 29 in Geneva to discuss Nagorno-Karabakh.

Turkey, a strident backer of Azerbaijan, has demanded a bigger role in the mediating body.

Russian President Vladimir Putin and his Turkish counterpart Recep Tayyip Erdogan spoke on the phone on October 27 about Nagorno-Karabakh, as well as Syria and Libya.

The Kremlin said Putin expressed his concerns over increased involvement of fighters from the Middle East in the conflict.

There have been more reports outlining evidence that Turkey has deployed jihadists from Syria in the conflict zone to fight for Azerbaijan.

The Drive, meanwhile, on October 26 used satellite images to establish that Turkish F-16 fighter planes that were previously parked at an airport in Ganja, Azerbaijan, were moved to the Gabala dual-use military-commercial airport in a north-central part of the country after Ganja was shelled.

Putin said on October 22 that Moscow believed nearly 5,000 people have been killed in the latest fighting.