Additional NASAMS air and ballistic missile defence systems have been put on combat duty in Ukraine, Ukrainian president Volodymyr Zelenskyy said on Tuesday.
"Additional NASAMS systems from our partners have been put on combat duty," Mr Zelenskyy posted on social media following a meeting of top Ukrainian officials.
He added that it was a "timely reinforcement of our air defence for the winter," without elaborating.
In October, Lithuania announced that it would provide Ukraine with two NASAMS launchers. It is not known from which partner the systems were transferred.
The Generation II SAM battery consists of 12 launchers (each carrying six missiles), eight radars, one fire control centre, one vehicle with an electronic optical camera and one Tactical Control Cell vehicle.
The probability of hitting a target with a single missile is 85 percent. The maximum speed of the target is 1 km/s.
NASAMS was first put on combat duty in Norway in 1994. Since then, three generations of the SAM have been produced.