President Serzh Sargsyan and his Azerbaijani counterpart Ilham Aliyev met Saturday, December 19 in Bern, Switzerland.

The Presidents’ private talks lasted a little more than an hour, the OSCE Minsk Group U.S. Co-chair James Warlick said in a tweet.

According to Armenian President's spokesman Vladimir Hakobyan, the meeting was held behind closed doors, with the Co-chairs and Foreign Ministers joining the leaders afterwards.

The two Presidents met against the backdrop of escalation along the contact line between Nagorno Karabakh and Azerbaijan.

Earlier on Saturday, a spokesperson for Armenia's Defense Ministry, Artsrun Hovhannisyan said the situation was extremely tense on the Armenian-Azerbaijani border at night. Artillery weapons, tanks were used, with several Azerbaijani subversive groups thrown back to their positions, he noted.