There is also speculation as to the health of the Russian president, who has been said by some to be showing signs of serious illness - despite this being denied by the CIA.
On Wednesday, Mr Putin cancelled a visit to Pskov - a key strategic city which borders Latvia and Estonia to Russia’s west - with the Kremlin saying that flying conditions there were not conducive due to the weather.
This follows him pulling out of a planned inspection of a tank factory on Monday, Boxing Day.
Pskov airport has been open throughout, as has St Petersburg - where Mr Putin is based - and satellite pictures have shown clear skies around it.
Press speculation has built around the health of the president after he was pictured with discoloured hands and appearing out of breath on state visits.
Rumours about his health have intensified as Ukraine digs in with its defence against the Russian attack which began with the invasion in February.
On Wednesday, Russian forces stepped up mortar and artillery attacks on the recently liberated city of Kherson in southern Ukraine. Ukraine's military said this occurred while also exerting constant pressure along front lines in eastern regions of the country.
Russia reportedly fired 33 missiles from multiple rocket launchers at civilian targets in Kherson in the 24 hours to early Wednesday, the general staff of Ukraine's Armed Forces said.
Fighting was particularly intense around the strategic eastern city of Bakhmut in Donetsk province and Svatove, further north in Luhansk province, Britain's defence ministry reported.