Andrew Peek, the senior director for European and Russian affairs at the National Security Council, has been placed on administrative leave pending a security-related investigation, people familiar with the situation tell Axios.Driving the news: Peek had been expected to attend the World Economic Forum in Davos, Switzerland next week, where President Trump is expected to meet with a number of world leaders as the impeachment trial takes place back in the Senate.Peek declined to comment.White House and National Security Council officials declined to discuss the situation. "We do not discuss personnel matters," the NSC said in a statement to Axios. Why it matters: Peek's responsibilities at the NSC, and before that at the State Department, touch on a number of sensitive areas. He took on the same role as impeachment witnesses Fiona Hill and Tim Morrison.He joined the NSC in November after serving as a deputy assistant secretary at the State Department, where he focused on Iraq and Iran.He previously served as a strategic adviser to now-retired Marine Gen. John Allen when Allen was commander of the NATO-led International Security Assistance Force in Afghanistan.Go deeper: NSC staffer denies having secret Ukraine conversations with Trump