Ukraine Investigates Reports of Surveillance of Marie Yovanovitch

Newly released documents suggest that Ms. Yovanovitch was being watched in Kyiv while she was the U.S. ambassador there.

The police in Ukraine have opened a criminal investigation into whether allies of President Trump had the United States ambassador to the country under surveillance while she was stationed in Kyiv, the Ukrainian government said on Thursday.

Democrats in the House of Representative on Tuesday revealed text messages to and from Lev Parnas — an associate of Rudolph W. Giuliani, the president’s personal lawyer — pointing to surveillance of the ambassador,...