NATO's chief is meeting European Union defense ministers to discuss boosting cooperation between the military alliance and the 28-nation bloc to tackle looming threats to the region.

Secretary-General Jens Stoltenberg says he will use Friday's meeting in Amsterdam to talk about "how we can work more closely on challenges like hybrid threats, like working together to stabilize our neighborhood in the South."

Stoltenberg also has welcomed the Obama administration's announcement this week that it will propose quadrupling spending on its troops and training in Europe as part of the U.S. military's accelerating effort to deter Russia after Moscow's annexation of Crimea and incursion into eastern Ukraine.

Stoltenberg called the U.S. move "an important sign and part of the adaptation of the Alliance to a more demanding security environment."