NATO Secretary General Jens Stoltenberg arrives to attend the EU summit in Brussels, Belgium, December 14, 2017. REUTERS/Yves Herman

BRUSSELS (Reuters) - NATO chief Jens Stoltenberg welcomed greater cooperation between the Western military alliance and European Union on Thursday, saying the two were stronger together.

“Forces and capabilities developed under EU initiatives have to be available also for NATO because we only have one set of forces,” NATO’s secretary general told reporters on arrival at a summit of European leaders. “Together we are stronger.”

With Brexit also on the summit’s agenda, he said that Britain’s withdrawal from the EU would not change its relationship with the military alliance.