"Foreign citizens or stateless persons who sign a contract to serve in the Russian Armed Forces... for at least one year and take part in military operations for at least six months" will be eligible for the simplified application procedure, the decree said.

Foreigners who are injured in combat before six months of fighting are up and cannot return to the battlefield will also be eligible, according to the decree.

The document comes over a week after Putin announced a mobilisation of hundreds of thousands of Russian men to bolster Moscow's army in Ukraine, which has recently suffered setbacks, particularly in the east of the country.

The decree appeared to be targeted towards thousands of citizens of ex-Soviet countries in Central Asia who live and work in Russia and receive better salaries compared to their poorer, home countries.

Four of the five -- Uzbekistan, Tajikistan, Kyrgyzstan and Kazakhstan -- have recently urged their citizens not to join foreign armies.

The spouses, children and parents of foreigners signing a contract with the army will also be able to benefit from simplified access to Russian nationality, according to the decree.