The officials said the defense ministers in private meetings Thursday talked about the effects that such disputes and sovereignty violations can have and noted that there is strength in unity. The officials spoke on condition of anonymity because they weren't authorized to discuss the talks publicly.
The Ukraine issue was one of many at the three-day gathering hosted by Defense Secretary Chuck Hagel. The defense leaders also discussed increasing cooperation in disasters and humanitarian crises.
Hagel says Singapore proposed using its Changi Naval Base as a crisis coordination center. He says the idea will be pursued.