Breaking news:10 Months Later, Russia Admits Deadly Downing of Azerbaijani Plane:see more 👇

President Vladimir Putin’s rare acknowledgment of a Russian military mistake came as relations have deteriorated between the two former Soviet states.

President Vladimir V. Putin on Thursday acknowledged Russia’s responsibility for the deadly downing of an Azerbaijani jet late last year, trying to heal a rift between the two former Soviet nations over the Kremlin’s monthslong deflection of blame.

Thirty-eight people were killed on Christmas Day when an Embraer 190 operated by Azerbaijan Airlines crashed on the shores of the Caspian Sea. The plane, carrying 62 passengers and five crew members, was en route from Baku, the capital of Azerbaijan, to Grozny, the capital of the Russian region of Chechnya.

Evidence quickly emerged that the jet had been shot down by Russian aerial defense systems that were targeting Ukrainian drones. Russian officials denied that Moscow had been involved, enraging Azerbaijani officials and citizens.

On Dec. 28, Mr. Putin offered a rare public apology to Ilham Aliyev, the Azerbaijani president, for what he called a “tragic incident,” but the Russian leader stopped short of taking responsibility.

The two leaders met for the first time since the crash during a gathering of regional leaders on Thursday in Tajikistan. Mr. Putin reiterated his apology and publicly admitted for the first time that Russia had caused the disaster, saying that two of its air-defense missiles had detonated near the jet after Ukrainian drones entered Russian airspace near Grozny.

It was Russia’s “duty,” Mr. Putin said, according to remarks released by the Kremlin, “to give an objective assessment of everything that happened and to identify the true causes.”

He indicated that Russia would be willing to pay unspecified damages to the victims’ families after a “legal assessment” of the incident.

Mr. Putin publicly acknowledges mistakes by the Russian military extremely infrequently. More than a decade after Russian missile defense brought down a Malaysia Airlines flight over eastern Ukraine, killing 298 people, Moscow continues to deny its role in the crash.