President Donald Trump withdrew his nominee to lead the National Park Service, adding to the uncertainty looming over the agency, which the Trump administration is seeking to shrink.

The White House gave notice of the withdrawal of the nomination for hospitality executive Scott Socha on Monday as part of an announcement on the latest nominees and withdrawals for agency positions. The NPS, which is part of the Interior Department, is responsible for managing the country’s national parks, monuments, and other historical sites.