SINGAPORE—China blocked Wells Fargo banker Chenyue Mao from leaving the country because she is required to assist in a criminal probe, China’s Foreign Ministry said Monday, marking Beijing’s first confirmation of the exit ban.

China's foreign ministry said on Monday Chenyue Mao, the Wells Fargo banker who has been blocked from leaving the country, was involved in a criminal case and was obliged to cooperate with the investigation.

Beijing confirmed that China-born, Atlanta-based Mao Chenyue is banned from leaving the country. This comes during a trade war with the Trump administration.