Russia, France - and now the United States.
It does not seem to matter which country is negotiating a ceasefire around the disputed Nagorno-Karabakh region between Armenia and Azerbaijan.
The latest agreement was announced by Washington on Sunday and entered into force at 8 a.m., local time, on Monday morning.
Barely an hour later, the first allegations of violations of the so-called "humanitarian ceasefire" came.
Blame each other
According to the Foreign Ministry of Azerbaijan, Armenian forces have shelled several villages, while Armenia accuses the neighboring country of artillery fire along the front line of the conflict.
The battles over Nagorno-Karabakh are in their second month. International mediators are desperately trying to put an end to the unrest, which since September 27 has cost hundreds of lives on both sides of the conflict.