By Michelle Nichols UNITED NATIONS (Reuters) – A United Nations Security Council meeting on Monday on Russia’s troop build-up on Ukraine’s border will be “an opportunity for Russia to explain what it is doing,” a senior U.S. administration official said, as Russia signaled it could seek to stop the public council discussion. “While I do think there will be some deflection and perhaps some disinformation … there’s also a clear opportunity for Russia to tell the Security Council whether they see a path for diplomacy or are interested in pursuing conflict,” said the U.S. official, speaking on c…