Russia has warned it would walk out of the Geneva talks on Ukraine if Kiev uses force against protesters in eastern Ukraine.

      In a phone call with US Secretary of State John Kerry, Russian Foreign Minister Sergey Lavrov said that any clampdown on the people in places like Donetsk or Slavyansk would spell a failure for the four-party talks scheduled for April 17 in Geneva.

      During the same phone call, the US warned Russia of further sanctions if Moscow does not “take steps to de-escalate in eastern Ukraine”.

      According to the official Twitter account of the State Department, John Kerry “expressed strong concern that attacks today by militias in Ukraine were orchestrated.”

      Militants are equipped with Russian weapons and the same uniforms as those worn by Russian forces that invaded Crimea, read the statement.

      Earlier, the US and the EU have introduced asset freezes and travel bans on a number of individuals and have vowed further action if Russia moved further into eastern Ukraine.

      Pursuant to Executive Order 13661 signed by President Obama on March 16, 2014, the US Treasury will freeze any of assets belonging to 20 Russian individuals and one bank within U.S. jurisdiction and prohibit any transactions with them.

      Among them are 16 officials, including Viktor Ozerov, Vladimir Dzhabarov, Evgeny Bushmin, Nikolai Ryzhkov, Sergey Zheleznyak, Sergey Mironov, Aleksandr Totoonov, Oleg Panteleev, Sergey Naryshkin, Viktor Ivanov, Igor Sergun, Sergei Ivanov, AlexeyGromov, Andrey Fursenko, Vladimir Yakunin, and Vladimir Kozhin. Also on the list are four “members of the inner circle”, including Gennady Timchenko, Arkady Rotenberg, Boris Rotenberg, and Yury Kovalchuk.