The Russian president was in St Petersburg for the International Economic Forum.

As CNN reports, Vladimir Putin has threatened Nato with “grave danger” if the organization were to take a greater part in the war, notably by delivering arms to Ukraine.
“NATO, of course, is dragged into the war in Ukraine, what are we talking about here?” the Russian president said at the St Petersburg International Economic Forum on Friday. “Deliveries of heavy weapons to Ukraine continue, and NATO is now considering giving jets to Ukraine,” he continued. Vladimir Putin was referring to the delivery of F-16 fighter jets by certain members of the organization.
Vladimir Putin also claimed that Western tanks had been destroyed by the Russian army, “including Leopards”, he added. “And if they are based abroad, but used in combat, we will see how to hit them, and where we can hit these assets that are being used against us in combat,” said the Russian president, before adding: “There is a serious danger here of dragging NATO into this military conflict.”
Putin then dwelt on the nuclear issue: “Nuclear weapons are created to guarantee our security in the broadest sense and the existence of the Russian state,” he asserted. “Moreover, we have more such weapons than NATO countries. They know this, and they continue to push for negotiations on reductions.