Armenia accused Azerbaijan on Tuesday of refusing to honor a recent Armenian-Azerbaijani agreement to expand an international mission monitoring the ceasefire regime in the Nagorno-Karabakh conflict zone.

According to the U.S., Russian and French mediators co-heading the OSCE Minsk Group, the Armenian and Azerbaijani foreign ministers reached the agreement “in principle” at their January 18 meeting in Krakow, Poland.

The Russian co-chair, Igor Popov, specified later in January that the deal would allow the OSCE to hire seven more members for its small truce-monitoring team. He said the conflicting parties and the mediators still need to work out “some technical details” of this arrangement.

“We agreed to the co-chairs’ proposal to enhance the capacity of the team of the personal representative of the OSCE chairman-in-office, and that was announced by the co-chair countries and Armenia,” Foreign Minister Edward Nalbandian said on Tuesday. “Azerbaijan is still refusing to make any reference to that agreement and to honor that agreement.”

The presidents of Armenia and Azerbaijani already agreed to the expansion of the OSCE team when they met in Vienna in May 2016. The team led by Andzrej Kasprzyk consists of a small number of officials who regularly travel to Karabakh and the Armenian-Azerbaijani border to briefly monitor the parties’ compliance with truce agreements reached in 1994 and 1995.

Azerbaijan officially stated in March 2017 that it will not allow the OSCE to deploy monitors on the Karabakh frontline “in the absence of withdrawal of the Armenian troops from the occupied territories.” Baku has been just as reluctant to allow international investigations of truce violations there, which were also agreed upon in May 2016.

Presidents Serzh Sarkisian and Ilham Aliyev pledged to intensify the peace process and bolster the ceasefire at their most recent meeting held in Geneva in October 2017. Their foreign ministers held follow-up negotiations in December and January.

The U.S., Russian and French mediators visited Baku, Yerevan and Stepanakert in early February. They said in a joint statement that the warring sides pledged to “continue intensive negotiations.”

Aliyev is seeking a fourth term in office in a snap presidential election slated for April 11. The ballot will be held two days after Sarkisian completes his second and final presidential term. Sarkisian is tipped to become prime minister immediately after Armenia is transformed into a parliamentary republic later in April.