UNITED NATIONS (AP) -- Diplomats say Ukraine's new prime minister will brief the U.N. Security Council at an open meeting Thursday.
The diplomats said Prime Minister Arseniy Yatsenyuk will travel to New York from Washington to address the U.N.'s most powerful body. They spoke on condition of anonymity because an official announcement has not been made.
Yatsenyuk was in Washington on Wednesday to meet with President Barack Obama at the White House.
Yatsenyuk is expected to reiterate that Sunday's referendum on whether Ukraine's Crimea region should become part of Russia is illegal.
Russia has become increasingly isolated in the Security Council, with even close ally China reaffirming Ukraine's territorial integrity. But Moscow can still block any council action using its veto power.