NATO said today it was concerned by the "increasing sophistication" and number of weapons deployed by pro-Russian rebels in eastern Ukraine, following the crash of a Malaysian Airlines jet there.
"We are concerned about the growing number of heavy weapons being operated ... As well as the increasing sophistication of these systems," a NATO official said.
"We have seen that Russia continues to allow mercenaries and heavy weapons to flow across its borders into Ukraine," the official added.
Asked about what the US-led military alliance knew of the circumstances of the crash of flight MH17 with the loss of nearly 300 lives, the official said he could not comment on intelligence matters.
However, the official said NATO did have two AWACS surveillance aircraft on patrol over Poland and Romania at the time of the incident.
"Their flights records are currently being reviewed," but given their distance from the crash site, "we do not expect that our aircraft recorded the incident," the official said.
The AWACs planes were sent to the region earlier this year as NATO sought to bolster its allies, and especially Poland, who were unnerved by a newly-assertive Russia.
NATO head Anders Fogh Rasmussen called Thursday for an international inquiry into the crash amid suspicions that the rebels shot down flight MH17 down using missiles.
