EU and NATO leaders vowed to step up cooperation against hybrid threats on a visit to Lithuania dominated by talks on the Belarus migrant crisis and Russia"s military build-up near Ukraine, writes Euronews.

NATO Secretary-General Jens Stoltenberg also repeated his call on Russia to “de-escalate” its military build-up on the border with Ukraine and warned of “costs and consequences” if it used force.

The visit by Stoltenberg and European Commission chief Ursula von der Leyen comes ahead of a meeting of NATO foreign ministers including US Secretary of State Antony Blinken in Latvia this week.

Stoltenberg and von der Leyen both accused Belarus of orchestrating the migrant crisis on its border as a “hybrid” threat against the European Union - a charge that the regime has denied.

A hybrid threat is a security challenge combining traditional military means and non-military tactics such as disinformation.

“To respond to such events, it is important that the European Union and NATO work hand in hand”, - von der Leyen said at a joint press conference with Stoltenberg and Lithuanian leaders.

Stoltenberg said: “We discussed how we could step up our joint work between NATO and the EU including through a new joint declaration because we are stronger and safer when we work together”.