Russian President Vladimir Putin remains undecided about whether to expand the war in Ukraine, American officials believe, as a fusillade of aggressive rhetoric has set the stage for a suspense-filled holiday season.

Putin sent mixed signals Thursday, as he claimed that U.S. and European powers aspire to orchestrate a breakup of the Russian state but also allowed that recent diplomatic exchanges have been “positive.” NATO Secretary General Jens Stoltenberg plans to convene a meeting of the NATO-Russia Council in January, but Russia’s aggressive posture spurred a series of conversations Thursday between U.S. and European officials who hope that the threat of economic sanctions will deter a conflict.