Nato defence ministers have decided to increase the military alliance's naval presence in the Black Sea in response to an increasingly aggressive Russia.
Secretary-General Jens Stoltenberg said that Nato will hold more war games and training in the strategically important sea, which borders allies Turkey, Bulgaria and Romania, but also Russia, Ukraine and Georgia.
Russia's naval fleet based at Sevastopol in Crimea has been a major concern for Nato.
Mr Stoltenberg told reporters after chairing the talks in Brussels that the move "will be measured, it will be defensive, and it will in no way aim at provoking any conflict or escalating tensions".
Several Nato allies are already providing troops for a 3,000-5,000-strong land force in Romania.