The US Department of State announced the temporary suspension of routine visa services at most overseas posts.
Any country with a travel advisory of 2, 3, or 4 will be affected. Among others, this includes the United Kingdom, Germany, China, Israel, South Korea, Italy, Japan, France, Ukraine, Russia, India, Denmark, Turkey, and Brazil. The Visa Waiver Program, which allows 90 day visas for certain nationalities, remains unaffected.
No timeline has been given. US Embassies and Consulates will continue to provide emergency visa services and American Citizens Services.