"Now we will have a spring-summer campaign - it is inevitable. The aggravation of the military actions will begin in a month, or half a month, or in a maximum of two [months]," Girkin said.

"According to the current situation, we understand that we will have again to clothe, shoe and equip 10,000 to 15,000 people, because their central supply is in a bad way," Girkin said.

Girkin, a Russian nationalist and Russian intelligence officer, claimed in an interview published in November in a nationalist Russian magazine that he and his team of special operations soldiers first “pulled the trigger of war” in the Donbas by occupying police and security offices in towns and cities in the region.

He said that after taking part in Russia’s invasion and annexation of Crimea, he crossed into eastern Ukraine with a team of about 50 Russian special ops soldiers.

His claims are corroborated by several videos from April last year that show teams of soldiers in unmarked uniforms taking over police and security offices in military-style operations. The offices were then occupied by “local militants.”

During his time in Ukraine, Girkin complained that too few locals were willing to fight on the side of the militants, and that not enough help was coming from Russia.

Russia initially denied claims that it had sent soldiers into Crimea to take over the peninsula, claiming the “little green men” who appeared in late February 2014 ahead of the annexation of Crimea were local “self-defense militias.”

However, Russian President Vladimir Putin has since admitted that Russian troops were behind the takeover, and has presented some with medals for taking part in the operation. The medals date the start of the operation as being on February 20, two days before former Ukrainian President Viktor Yanukovych abandoned his office and fled Ukraine amid massive public protests against his rule.

In a recent documentary on the annexation of the Ukrainian territory of Crimea by Russia that aired on Russian television, Putin also said that planning for the takeover of Crimea started before Yanukovych’s ouster. Previously he said the decision to take over Ukraine was taken only after a referendum was held in Crimea on the matter.

Russia also denies sending its troops into eastern Ukraine.