(Reuters) -President Volodymyr Zelenskiy signed a law allowing some convicts to join the armed forces as it battles to hold the line against Russian offensives in Ukraine's northeast, east and south, the parliamentary database showed on Friday.

Manpower has long been an issue for Kyiv's military as it fights a much larger and better-equipped foe. The problem has grown more acute in recent months, prompting authorities to introduce stricter measures for draft evaders.

The new law offers parole to convicts who sign a contract to join the army, a move that some officials have said could generate a maximum of 20,000 soldiers for the Ukrainian war effort.

Those convicted of the most serious crimes, such as the premeditated murder of two or more people, rape and crimes against national security, would still not be allowed to enlist.

Separately, Zelenskiy signed a law increasing fines for draft dodgers to up to 8,500 hryvnias ($218), according to the parliament's website. The average monthly wage in Ukraine is about $560.

The lack of manpower is seen by some military analysts as Ukraine's biggest problem. Weapons supplies that have been significantly delayed, particularly from Washington, are expected to reach the frontline soon.

Ukraine has already lowered the draft mobilisation age from 27 to 25. The upper limit is 60.

In tandem, the government has also temporarily suspended consular services for men of military age who reside abroad, complaining they were not helping the Ukrainian state fight for its survival.

Sweeping legislation overhauling the rules governing army mobilization comes into force on Saturday.

(Reporting by Yuliia Dysa; editing by Christina Fincher, William Maclean)