Kremlin sources tell Bloomberg that Putin is preparing to escalate the war in Ukraine. A growing number of Russian officials believe that could eventually mean a tactical nuclear weapon.

Russia is preparing to escalate its strikes on Ukraine after concluding that peace talks have hit a dead end, sources close to the Kremlin told Bloomberg.

Here’s what the sources said:

• Russia is weighing stepped-up conventional ballistic missile strikes on Kyiv, including the city center, and on infrastructure in other Ukrainian cities.
• Russian President Vladimir Putin will not end the war under pressure from economic sanctions or Ukrainian strikes on Russian oil refineries and logistics networks.
• Moscow increasingly views Ukrainian strikes as attacks by NATO member states because alliance members supply Kyiv with weapons and intelligence.
• Every mechanism for peace talks has collapsed, leaving the two warring sides back where they started. The Kremlin believes that it has already made concessions during the war and that each one weakened Russia’s position. In the absence of diplomacy, Moscow sees few ways to achieve its military goals other than further escalation.
• The intensifying Ukrainian strikes have led a growing number of Russian officials to believe that Putin could eventually take the extreme step of using tactical nuclear weapons in Ukraine.

Bloomberg said there are no signs that Russia is preparing to use tactical nuclear weapons in Ukraine. In the past, Russia has repeatedly made nuclear threats in an effort to intimidate Ukraine’s Western allies.

Alexander Gabuev, director of the Berlin-based Carnegie Russia Eurasia Center, told Bloomberg the risk of Moscow using tactical nuclear weapons remains extremely low.

Kremlin spokesman Dmitry Peskov did not respond to a request for comment.