Poland's Defense Ministry says it plans train about 50 Ukrainian army instructors this year, joining a NATO effort to improve Ukraine's defense capabilities as it struggles with a pro-Russia insurgency in its east.

The ministry said Tuesday that training sessions would take place in Poland in June, September and October.

Several other NATO members are also joining the NATO program known as the Defense Education Enhancement Program. Its aim is to bring Ukraine's forces up to the standards of the Western alliance.

Poland has been a leading European critic of Russian actions in Ukraine since the conflict erupted last year with Russia's annexation of Crimea.