PARIS - Facing off in Europe's capitals, Russia and the West began trying to build the elements of a diplomatic solution to Europe's gravest crisis since the Cold War - even as the West appeared increasingly resigned to an entrenched Russian presence in Crimea. NATO hit back by putting Russia on suspension, and the European Union extended $15 billion in aid to Ukraine, matching the amount the country's fugitive president accepted from Moscow to turn his back on an EU trade accord.As peace efforts progressed in Paris and Brussels, volatility reigned on the ground in Ukraine: A special U.N. envoy visiting Crimea came under threat by armed men who forced him to leave the region. Meanwhile, hundreds of demonstrators, many chanting "Russia! Russia!" stormed a government building in eastern Ukraine - renewing fears that turmoil could spill out of Crimea and engulf other Russian-dominated parts of Ukraine.Ukraine's prime minister told The Associated Press in his first interview since taking office that he still feared Russian President Vladimir Putin might attempt more land grabs: "Mr. President," Arseniy Yatsenyuk said, "stop this mess."Yatsenyuk vowed to keep Crimea as part of Ukraine, but expressed openness to granting it more autonomy. Ukraine's foreign minister, Andriy Deshchytsia, told the AP that pro-Russian citizens in Crimea must be willing to replace armed forces with international observers if they want a vote on more self-rule.But most of the bargaining chips Wednesday belonged to Russia, whose troops are fanned out across Crimea and control most of its strategic facilities.A growing chorus of prominent American voices expressed resignation that Crimea was lost to Russia: "I'm not optimistic they're going to leave," said Michael McFaul, who served as Obama's ambassador to Russia until last week.U.S. Secretary of State John Kerry, Russian Foreign Minister Sergey Lavrov and several European counterparts conducted an intense round of diplomacy in Paris to try to find an exit strategy in Ukraine. While negotiations were inconclusive, top European officials expressed optimism that at least the two sides were talking - and making progress."For the first time, starting with this meeting in Paris, something moved in the right direction," said French Foreign Minister Laurent Fabius.Lavrov, speaking in Spain before meeting with Kerry, warned against Western support of what Moscow views as a Ukrainian coup, saying that could encourage government takeovers elsewhere."If we indulge those who are trying to rule our great, kind historic neighbor," Lavrov said, "we must understand that a bad example is infectious."Russia expressed openness to international mediation, and the talks were a "work in progress," said a French diplomat on condition of anonymity because of government policy. But a major sticking point has been Moscow's refusal to recognize Ukraine's new government much less sit down at the table with them."I wish I could give you some good news," said Polish Foreign Minister Radoslaw Sikorski, "but unfortunately it hasn't been possible to bring together the foreign ministers of Ukraine and Russia."