The EU's executive has concluded a study of the cost to member states of imposing economic sanctions on Russia and has handed individual assessments to all 28, diplomats said Wednesday.

The European Commission assessed the potential impact on each of the bloc's 28 economies of agreeing trade and financial sanctions over the Ukraine crisis and handed the data in individual envelopes to EU ambassadors, said an EU diplomat speaking on condition of anonymity.

The head of the famed Russian space-rocket company Energia that makes the Soyuz spacecraft faces a criminal investigation into alleged abuse of office, Russia's Investigative Committee said on Wednesday.

Vitaly Lopota, president of Energia, is suspected of approving unauthorized loans to an international space consortium, Russia's equivalent of the FBI said in a statement.

U.S. senator John McCain on Wednesday described the West's response to Russian actions in Ukraine as "almost laughable", saying a stronger stance is needed to keep the Kremlin in check.

The recent U.S. and EU sanctions against Russia were "the weakest response imaginable", the Republican senator told reporters in the Lithuanian capital Vilnius while on a tour of the Baltic states.

Moldova's pro-Russian breakaway region of Transdniestr on Wednesday called on Russia and the international community to recognize its independence, as fears grew that it could become a new flashpoint in East-West tensions.

The leader of Transdniestr, in an interview with Agence France Presse, called on the EU to recognize the Russian-speaking statelet as independent, saying it was vital to ensuring stability in the region following rising tensions in Ukraine.

U.S. Secretary of State John Kerry left Wednesday for Geneva for high-stakes talks on Ukraine, armed with the threat of more sanctions against Moscow if diplomacy fails, as tensions on the ground escalated sharply.

The U.S. and the European Union will hold their first four-way talks with Ukraine and Russia on Thursday to address a worsening crisis, although U.S. officials have set low expectations for the meeting, still smarting from a slew of failures in past weeks.

Iran's Foreign Minister Mohammad Javad Zarif will travel to Russia next week for a meeting of the countries that border the Caspian Sea, the official IRNA news agency reported.

"Mr. Zarif will arrive in Russia on Tuesday,' for the gathering of the Caspian Sea littoral states, Iran's ambassador to Russia, Mehdi Sanaei, wrote on his Facebook page.

NATO said Wednesday it will deploy additional air, sea and land forces in eastern Europe in response to the worsening crisis in Ukraine and take further action if needed.

"Today we have agreed a package of military measures," NATO head Anders Fogh Rasmussen said after a meeting of ambassadors of all 28 members of the transatlantic alliance.

Ukrainian and pro-Russian forces flexed their military muscles in the restive east of the country on Wednesday, a day ahead of high-level diplomatic talks on the escalating crisis.

Ukraine's defense ministry said that pro-Russian militants had seized six armored vehicles dispatched by Kiev to the eastern town of Kramatorsk to quell a separatist insurgency.

Economic sanctions by Europe against Russia "would destroy Cyprus's economy," Nicosia's foreign minister Ioannis Kasoulides said in a German newspaper interview Wednesday.

"There are very strong economic ties between Cyprus and Russia. If sanctions are really necessary, then every member state should decide for itself whether to take part," Kasoulides said.

Russian leader Vladimir Putin warned that Ukraine is on the verge of civil war, the Kremlin said Wednesday, after the Kiev government sent in troops against pro-Moscow separatists in the east of the country.

"The Russian president remarked that the sharp escalation of the conflict has placed the country, in effect, on the verge of civil war," the Kremlin said in a statement on telephone talks between Putin and German Chancellor Angela Merkel.