Senior American military officers are discussing the possibility of providing Ukraine with more precise intelligence that would allow it to target missiles held by pro-Russian forces, US officials said Monday.
But no decision is imminent and some officials are concerned such a move could backfire by escalating the conflict between Ukraine and the rebels backed by Moscow.
"That's part of the discussions," said one defense official, who spoke on condition of anonymity, referring to the possible enhanced intelligence sharing.
"It's all part of looking at how we can help the Ukrainians," the official told AFP. But he added there were risks in providing Ukrainian forces with information that could help them strike at pro-Russian fighters in the country's east.
The New York Times first reported that the Pentagon and spy agencies were looking at sharing more precise, real-time intelligence with Kiev to enable its military to go after surface-to-air missiles blamed for taking out several of its aircraft.
The White House has yet to hold a debate on the issue among high-level officials, the paper reported over the weekend.
A second Pentagon official downplayed the likelihood of the move and underlined the dangers involved.
"There's not enough military equipment that Washington could provide to counter Russian influence," said the official, who spoke on condition of anonymity.
"There's a risk that the more weapons we provide to the Ukrainians, the more Russians escalate and step up their role," the official said.
For the moment, President Barack Obama's administration has provided only limited intelligence to Ukraine and has avoiding supplying weapons to Kiev.
Instead, Washington has favored diplomacy, urging European allies to impose tougher sanctions on Moscow in hopes of forcing President Vladimir Putin to back off of his assertive stance on Ukraine.
Washington has accused Russia of expanding its military support for the separatists in recent weeks with deliveries of heavy weapons and last week alleged Russian units were firing artillery across the border at Ukrainian forces.
The Pentagon said Monday there has been no let-up in Russia's military buildup near Ukraine, including arms deliveries and training of separatists at a major staging area outside of Rostov.
"I can tell you that last week we saw a column of over 100 Russian vehicles moving into Ukraine," spokesman Colonel Steven Warren told reporters.
The column was unusually large and reinforced US concerns about Russia's actions in and around Ukraine, he said.
Pro-Russian separatists are suspected by the West of using SA-11 missiles to shoot down a Malaysian airliner on July 17, in an allegedly inadvertent strike by rebels who have targeted Ukrainian military aircraft.