Amid the ongoing military conflict over the disputed Nagorno-Karabakh region, the Foreign Ministers of Armenia and Azerbaijan separately met US Secretary of State Mike Pompeo here, according to the State Department.

The Department said in a statement that following the separate meetings with Azerbaijani Foreign Minister Jeyhun Bayramov and Armenian Foreign Minister Zohrab Mnatsakanyan, Pompeo urged to "end the violence and protect civilians" since the renewed clashes between the two nations erupted on September 27, with intense battles raging in the Nagorno-Karabakh region.

"The Secretary also stressed the importance of the sides entering substantive negotiations under the auspices of the OSCE Minsk Group Co-Chairs to resolve the conflict based on the Helsinki Final Act principles of the non-use or threat of force, territorial integrity, and the equal rights and self-determination of peoples," Department spokesperson Morgan Ortagus was quoted as saying in the statement.

Taking to Twitter, Pompeo said that "we discussed critical steps to halt the violence in the Nagorno-Karabakh conflict".

"Both must implement a ceasefire and return to substantive negotiations," he added.

Meanwhile, Mnatsakanyan told the Washington-based Voice of America radio network that the talks were "very good", as he left the State Department, where about two dozen demonstrators, mostly Armenians, were gathered outside.

When asked about a timeline for a ceasefire, he said: "We (will) keep working on that."

The meetings came in the wake of a failed second ceasefire which came into on October 18 in the conflict-ridden region.

Azerbaijan and Armenia traded accusations of violating the second ceasefire despite the two warring countries welcoming the truce.

Following trilateral negotiations between Russia, Azerbaijan and Armenia that lasted for over two hours in Moscow, the first ceasefire was enforced in the region on October 11.

Nagorno-Karabakh is a disputed territory which is internationally recognized as part of Azerbaijan but mostly governed by the Republic of Artsakh, a de facto independent state with an Armenian ethnic majority.

The area experienced flare-ups of violence in the summer of 2014, April 2016 and in July tjis year.

Armenia and Azerbaijan went to war over the region in 1988-94, eventually declaring a ceasefire.

However, a settlement was never reached.