"These incidents do not correspond to the Armenian and Azerbaijani presidents’ commitments to reach a peaceful resolution to the Nagorno-Karabakh conflict,” Psaki said on Jan. 5. "As an OSCE Minsk Group co-chair country, we do continue to urge both sides at the highest levels to engage in negotiations that could lead to a peace agreement and adopt measures to reduce the likelihood of such events along the line of contact and along the border. That continues to be our focus.”

Armenia said two of its soldiers were killed by Azerbaijani troops south and east of Nagorno-Karabakh on Jan. 3. Azerbaijan denied the claim.

Armenia captured nearly one-fifth of Azerbaijan’s internationally-recognized territory, including Nagorno-Karabakh and seven surrounding regions, in a war after the Soviet breakup in 1991.

Although major hostilities ended with a ceasefire in 1994, no peace agreement has been signed.

At least 19 soldiers were killed in August when skirmishes in and around Nagorno-Karabakh turned the deadliest in 20 years. 

Azerbaijan in November shot down an Armenian helicopter gunship that was flying near Azerbaijani army positions in Agdam District.