With tensions mounting over Ukraine's stability, the Obama administration is readying additional sanctions for Russia ahead of a Thursday meeting between U.S., Ukrainian, Russian and European Union officials aimed at resolving the crisis.

Secretary of State John Kerry spoke by phone with his French, German and British counterparts on Tuesday, but new sanctions are unlikely to be imposed before Thursday's talks in Geneva, according to State Department spokeswoman Marie Harf.

“Tomorrow will be the first opportunity for Russia, Ukraine, the EU and the United States to sit down at a table together and discuss a range of issues, including and most importantly, de-escalation, demobilization,” Harf told reporters during a Wednesday briefing.

U.S. officials want the Russian government to pull its forces back from the border and from the Crimean region of Ukraine, halt what they view as support for destabilizing actions by pro-Russian forces in the eastern part of the country and to call on those armed separatist groups to stand down and disarm.

Although Russia has yet to invade the rest of Ukraine, it has shown little willingness to comply with the West's demands and will likely rebuff the latest calls. The U.S. and Europe are expected to expand sanctions against leading Russian figures in the days following the Geneva meeting.

“We have additional sanctions prepared,” Harf said. “As we said, don't expect any before tomorrow's meeting, but if there are not steps taken by Russia to de-escalate, we will take additional steps, including additional sanctions.”

Those sanctions reportedly could target Igor Sechin, a longtime ally of Russian President Vladimir Putin and the president of Rosneft, the largest state-owned Russian oil company. Rosneft, has extensive ties to European and U.S. companies; BP owns 20 percent of it and it has a number of joint ventures with ExxonMobil.

The meeting also will give the parties the chance to discuss concerns about using Ukrainian dependence on Russian energy supplies as a weapon.

“We have been very clear about what they should and should not be doing when it comes to energy for Ukraine, and Europe and other folks as well,” Harf said.

Harf also had harsh words for Russian claims that Moscow is playing no role in pro-Russian separatists coordinated seizures of buildings and other areas in eastern Ukraine.

“What we're doing is responding to misinformation and falsehood that the Russian government is putting forward about its actions,” she said. “We have a responsibility to not let propaganda that's false stand.”