Several senior American military and intelligence officials are arguing that if Mr. Putin does not encounter significant resistance to Russia’s moves in Ukraine, he may be emboldened to go further. And a senior State Department official said Saturday that Secretary of State John Kerry supported sharing intelligence on the locations of surface-to-air missiles that Russia has supplied the separatists.

Providing the location of weaponry and military equipment for possible destruction — something the United States does for Iraq in its battle against Islamic extremists, for example — would not be technologically difficult. “We think we could do it easily and be very effective,” a senior military official involved in the discussions said. “But there are issues of escalation with the Russians, and the decision about whether it’s wise to do it” is complex.

Another senior official said there were questions of whether the Ukrainian military, even if given targeting coordinates, had the reach and the precision to strike Russian-supplied antiaircraft batteries. The trucks transporting the missiles move frequently, often back and forth across the border. And if any strikes missed their targets, they could cause civilian casualties or land in Russia, giving Mr. Putin an excuse to enlarge the conflict.

“Although providing the Ukrainian forces with target location data may seem like a panacea, the actual destruction of these mobile launchers by Ukrainian forces may prove quite a bit more difficult,” said Reed Foster, an analyst at IHS Jane’s.

Mr. Foster said that Ukrainian forces had not trained extensively on using intelligence from other countries, and that any Ukrainian warplanes trying to strike missile sites would be vulnerable to ground fire. Some officials say they are worried that the Ukrainian military has been infiltrated by Russian sympathizers and agents, meaning that if the United States gave locations for targeting, the separatists could have warning of attacks.

Still, the issue has become increasingly urgent. The Pentagon said on Friday that it had seen evidence that Russia was planning a major influx of new weaponry across the border, and that it believed multiple-rocket launchers would soon be delivered from Russia.

American officials also said they had evidence that Russia was firing artillery from within its borders to attack Ukrainian military positions.