Russian President Vladimir Putin has ordered increased border security to allow the rapid movement of Russian troops and civilians into Ukrainian areas now under Moscow's control.

In a message on the occasion of Border Guard Day, Putin said that its task is to reliably cover the lines near the combat zone.

The intensity of attacks in Russia has increased in recent weeks, mainly through drone attacks in areas along the border with Ukraine, but also further into Russia, including yesterday against an oil pipeline northwest of Moscow.

"It is necessary to ensure the rapid movement of military and civilian cars and trucks, including food and humanitarian aid from construction materials sent to the new subjects of the Russian Federation," Putin said in a message posted on the Kremlin's Telegram channel.

The regions of Kherson, Zaporizhia, Luhansk and Donetsk are the four regions in Ukraine that Putin declared annexed by Russia last September after referendums that Kiev described as a travesty. Russian forces only partially control the four districts.