The presidents of Armenia and Azerbaijan will meet in Vienna early next week for talks that will be co-hosted by U.S. Secretary of State John Kerry and his Russian and French counterparts, the U.S. State Department said on Friday.

State Department spokesman John Kirby confirmed the meeting in a statement that detailed Kerry’s travel schedule for the next few days.

“Secretary Kerry will travel to Vienna, Austria, May 16-17 … Together with Russia and France, the United States will also co-host a meeting on the Nagorno-Karabakh conflict with Armenian President [Serzh] Sarkisian and Azerbaijani President [Ilham] Aliyev,” Kirby said.

Plans for the Armenian-Armenian summit in Vienna were first announced by senior Russian diplomats on Thursday. They said it will be primarily aimed at bolstering the ceasefire regime along the Karabakh “line of contact” following last month’s heavy fighting between Armenian and Azerbaijani forces deployed there.

Sarkisian’s and Aliyev’s offices did not confirm the upcoming meeting as of Friday evening, however.

“We report on the visits and meetings of the president of the republic in a proper manner and in due course,” Sarkisian’s press secretary, Vladimir Hakobian, told RFE/RL’s Armenian service (Azatutyun.am). He declined to comment further.

The Vienna meeting most probably topped the agenda of Foreign Minister Edward Nalbandian’s talks with France’s Foreign Minister Jean-Marc Ayrault and State Secretary for European Affairs Harlem Desir held in Paris on Thursday and Friday respectively. Ayrault, Kerry and Russian Foreign Minister Sergey Lavrov will be present at the Aliyev-Sarkisian talks.

According to the Armenian Foreign Ministry, Ayrault and Nalbandian agreed on the need to introduce a mechanism for international investigations of truce violations and deploy more OSCE monitors in the conflict zone.

Meanwhile, after several days of relative calm on the Karabakh frontlines the warring sides accused each other of opening intensive mortar fire there on Friday evening. The Karabakh Armenian army said Azerbaijani forces fired about 120 mortar rounds on its positions in Karabakh’s northeast.

Azerbaijan’s Defense Ministry, for its part, said the Armenian side shelled an Azerbaijani village located several kilometers northeast of Karabakh. It said its frontline troops are carrying out “retaliatory strikes on enemy positions.”

The ministry said earlier in the day that one Azerbaijani soldier was killed at an unspecified section of “the line of contact” on Thursday. The Karabakh Defense Army reported a combat death within its ranks late on Wednesday.

The ceasefire seemed to be largely holding when an RFE/RL correspondent visited Armenian positions southeast of Karabakh on Friday morning. “There are few gunshots right now,” one of the soldiers deployed there said. “When the situation gets a bit more tense we act so that they know that our guys stand firm here.”

“We don’t leave unanswered any action against us,” another soldier told RFE/RL’s Armenian service (Azatutyun.am).