The top NATO commander said Wednesday that the remaining Russian troops on the Ukraine border look like they intend to stay there, while rebel forces inside Ukraine continue to destabilize the Kiev government.

The top NATO commander said Wednesday that the remaining Russian troops on the Ukraine border look like they intend to stay there, while rebel forces inside Ukraine continue to destabilize the Kiev government.

U.S. Air Force Gen. Philip Breedlove said NATO needs to consider having a long-term troop presence deployed in the region “for as long as required” to address the Russian threat.

Breedlove’s comments came at a meeting Wednesday of NATO defense ministers, following President Barack Obama’s announcement that the U.S. will boost its military presence in Europe in response to Russia’s annexation of Ukraine’s Crimean region. Obama has said he will ask Congress to provide up to $1 billion to fund the effort.

At one point officials said Russia had up to 40,000 forces along Ukraine’s border, but the bulk of the troops have been withdrawn or are in the process of pulling out. U.S. officials have said they believe roughly seven battalions of Russian troops remain, but that number may be smaller now. Breedlove would not provide an estimate.

Speaking to reporters Wednesday, Breedlove said NATO needs “to have a much more responsive force to address this new threat that we see.” He said the allies will consider where the force should be positioned and whether it should move in and out on a rotational basis or remain in the region as long as needed.

He said he has recommended that NATO consider prepositioning military equipment in the region, but no final decisions have been made yet.