'More than 90 percent of Russian airstrikes have hit opposition forces'

More than 90 percent of Russian airstrikes inside Syria have hit opposition forces and not ISIL or al-Qaeda-affiliated targets, a U.S. official said Wednesday.

"They've been largely against opposition groups that want a better future for Syria and don't want to see the [Bashar] Assad regime stay in power," State Department spokesman John Kirby said during a press briefing.

Kirby noted that Russia's current actions in Syria are "largely reactive" to international pressure against Assad.

"I wouldn't call what they're doing a strategy," Kirby said. "It's a failing tactic to take because keeping him in power, even if it's because you want to get to mutual consent, propping him up only prolongs the conflict."

Kirby reiterated that the situation in Syria would not change if Assad stayed in power and received support from Russia, adding that Russia's current activities in the region are a "mistake" and not good for Syria's future.

Shortly after President Barack Obama and Russian President Vladimir Putin met in New York last week, the U.S. announced that both countries would open "lines of communication" to de-conflict air operations in Syria.

The day after the meeting, however, Russian warplanes began striking Syrian opposition targets inside Syria.

"The U.S. continues to wait for the Russians to provide a formal response to the presentation that was made last week to establish some basic de-confliction efforts," said White House spokesman Josh Earnest.

"Russia is being dragged deeper and deeper into a quagmire and the long-term interests of Russia are not well-served by this stepped up military investment inside of Syria," he said.

Meanwhile, some media reports have claimed the Iraqi government has welcomed Russia's airstrikes in Syria but Earnest said none of the 65 members of the U.S.-led coalition members fighting ISIL have offered support or encouragement to Russia for its actions. Iraq is a coalition member.

While Moscow insists it is targeting only ISIL and other affiliated groups, Western countries and their Gulf allies believe moderate opponents of Assad – along with civilians – are bearing the brunt of the Russian airstrikes.

Russia and the U.S. have different views on fighting ISIL. The U.S. wants to destroy ISIL and replace Assad, but Russia wants to fight only ISIL, with Assad's help.

Differences aside, Washington is seeking Russia's inclusion in a coalition of more than 60 nations committed to fighting the militants.