By Fatos Bytyci PRISTINA (Reuters) – Kosovo President Vjosa Osmani has asked U.S. President Joe Biden to use Washington’s influence within NATO member states to help her country join the military alliance. In a letter sent to Biden dated March 10th and seen by Reuters on Thursday, Osmani said that in the wake of Russia’s invasion of Ukraine, joining NATO was her main national security priority. “Kosovo’s membership in NATO has become an imperative,” Osmani said in her letter. “We express our faith and expectation that the U.S. will use its leadership and influence to actively support and advan…