Russia is considering halting foreign inspections of its strategic weapons arsenal, including nuclear-capable missiles, in response to "threats" from the West over the Ukraine crisis, the defense ministry said Saturday.

"The unfounded threats towards Russia from the United States and NATO over its policy on Ukraine are seen by us as an unfriendly gesture that allows the declaration of force majeure circumstances," a high-ranking defense ministry official, who was not named, said in a statement to all Russian news agencies.

Russia is open to having an "honest, equal" dialogue with foreign states on the crisis in Ukraine, Foreign Minister Sergei Lavrov said Saturday.

"We are open to an honest, equal and objective dialogue with our foreign partners to find a way to help all of Ukraine come out of the crisis," Lavrov said at a televised news conference in Moscow with his Tajik counterpart, in a clear reference to the West.

Russian President Vladimir Putin has seemingly been in the "deep freeze" since the Cold War and is applying its outdated KGB mentality in Ukraine, Britain's deputy prime minister said Saturday.

Speaking to The Guardian newspaper, Nick Clegg said Putin was applying "yesterday's divisions and arguments to today's problems".

Ukraine braced Saturday for new pro-Russian protests in the tense eastern city of Donetsk after Moscow threatened to stop crucial gas supplies to the country, further escalating hostilities with the West.

Donetsk, a focal point of the crisis engulfing Ukraine since the protests that toppled president Viktor Yanukovych, was expecting a large demonstration by activists demanding a secession referendum like the one planned for the Crimean peninsula.

The European Union needs to send observers to Ukraine as soon as possible, foreign ministers from the bloc's 10 eastern European and Nordic members plus Iceland and Norway said Friday.

"To help Ukraine in this period of transition, we support the establishment of a European Union led Observation Mission, which should be deployed as soon as possible," they said in a joint statement following ministerial talks in Estonia's eastern city of Narva.

Ukraine's far-right Pravy Sektor movement on Friday announced its leader Dmytro Yarosh would make a presidential bid in elections scheduled for May 25 and said it was ready to go to war with Russia.

The ultra-nationalist group played a crucial role in the frontlines of deadly protests that unseated former President Viktor Yanukovych last month and has been branded a neo-Nazi organization by Russia.

A United States warship crossed Turkey's Bosphorus Strait Friday, headed towards the Black Sea, as tensions simmer over Ukraine's Crimea region.

A coastguard boat was seen escorting the guided-missile destroyer, the USS Truxtun, an Agence France Presse photographer saw.

Russia does not want a new Cold War, President Vladimir Putin's spokesman said on Friday, as tensions rose over Russian-backed demands by Crimea to secede from Ukraine.

Dmitry Peskov was asked on a chat show on state television whether he could foresee a return to the clash of ideologies that polarized the world between 1945 and the fall of the Berlin Wall in 1989.

The House of Representatives on Thursday overwhelmingly approved U.S. financial aid to crisis-plagued Ukraine, but the Senate is unlikely to take up the measure until at least next week.

The lower chamber of Congress voted 385 to 23 in favor of the loan guarantees, the first tangible congressional response to Russia's incursion into its neighbor and former Soviet satellite.

The U.N. Security Council on Thursday launched another round of closed-door talks on the situation in Ukraine, its fourth such meeting in less than a week.

The meeting, convened at Britain's request, was expected to discuss the mission of U.N. special envoy to Crimea Robert Serry, who was forced to cut short his trip to the region when he was confronted by unidentified gunmen on Wednesday.