WASHINGTON (Reuters) - U.S. Secretary of State Mike Pompeo on Thursday said Turkey’s involvement in the conflict between Azerbaijan and Armenia has increased the risk in the region, reiterating his call for the issue to be resolved through diplomacy. Several hundred people have been killed in the deadliest flare-up of the decades-old conflict since a 1990s war over Nagorno-Karabakh killed about 30,000 people. Nagorno-Karabakh belongs to Azerbaijan under international law, but is populated and governed by ethnic Armenians. The clashes have raised concerns that Turkey and Russia, which also back opposing sides in the conflicts in Syria and Libya, may get dragged in. Rebuffing criticism from NATO allies, Turkey has accused Armenia of occupying Azeri territory and vowed full support for Azerbaijan. Ankara has repeatedly called on the Minsk Group, formed to mediate the conflict and led by France, Russia and the United States, to urge Armenia to withdraw from the region. “We now have the Turks, who have stepped in and provided resources to Azerbaijan, increasing the risk, increasing the firepower that’s taking place in this historic fight,” Pompeo said in an interview with broadcaster WSB Atlanta. “The resolution of that conflict ought to be done through negotiation and peaceful discussions, not through armed conflict, and certainly not with third party countries coming in to lend their firepower to what is already a powder keg of a situation,” Pompeo said. On Thursday, hopes of a humanitarian ceasefire sank as the death toll mounted and Armenia and Azerbaijan accused each other of launching new attacks. “We’re hopeful that the Armenians will be able to defend against what the Azerbaijanis are doing, and that they will all, before that takes place, get the ceasefire right, and then sit down at the table and try and sort through this,” Pompeo said.