Matthew Whitaker, the U.S. ambassador to NATO, said that NATO members should not tolerate deliberate actions of hybrid war, and the ​United States will stand by countries as they ‌deal with these incidents.

Axar.az reports, citing Reuters, that Whitaker said last month's attempted ​drone attack at Germany's Leipzig/Halle Airport, which Berlin ​has blamed on Russia, was more worrying ⁠than other recent incidents NATO members have ​faced due to Russian drones targeting Ukraine that strayed ​off course.

"Then you have what I would call the more concerning hybrid actions like we saw in Leipzig, like ​we have seen in Poland," Whitaker said​, speaking on the sidelines of a business conference in Italy.

NATO ‌members ⁠must be prepared, vigilant and also deliver a strong message when they are challenged by these events, he said.

"If we can identify who's doing ​it — which Germany ​did — we ⁠make sure we express strongly that is unacceptable and we will not ​tolerate it," Whitaker said.

Critical infrastructure, including ​energy ⁠assets, could be targeted and should be monitored by national authorities, he added.

The response to these challenges ⁠is ​primarily national, but the United ​States supports countries when they are dealing with these acts, ​he said.