"It's a training mission. Within its framework Polish officers will train officers and junior ranks of the Ukrainian Army," Schetyna said at a press briefing in Berlin.
Schetyna added that the training of Ukrainian troops by Polish instructors was not tied with the events in eastern Ukraine.
"Polish instructors in Ukraine are part of a wider NATO program that began last year. It doesn't concern the events in the east of Ukraine or the relations between Ukraine and Russia," Schetyna said.
In late February, UK Prime Minister David Cameron said that Britain would send military instructors to Ukraine to train local forces throughout March, developing an infantry training program with Ukraine.
Earlier in the day, the Russian Foreign Ministry said some 300 US troops had arrived to a base in western Ukraine to train government troops.
Russia-NATO relations have been strained since March 2014, when Crimea voted to secede from Ukraine and reunify with Russia, which prompted accusations from the alliance that Moscow had "annexed" the region. The organization suspended its cooperation with Russia over the allegations, which Russian authorities have denied.
