U.S. President Donald Trump | Pool photo by Zach Gibson/Getty Images Trump switches would-be US ambassador to Belgium to France Jamie McCourt, a Trump donor, was originally nominated to the post in Brussels.

France jumped the queue for a new U.S. ambassador; Belgium will have to wait.

Without explanation, U.S. President Donald Trump on Wednesday withdrew his nomination of Jamie McCourt, a campaign donor and former owner of the Los Angeles Dodgers baseball team, to be ambassador to Belgium and resubmitted her name to the Senate to be envoy to France and Monaco instead.

While the White House declined immediate requests for comments about the change, Trump has forged a closer relationship with French President Emmanuel Macron than perhaps any other European leader, as evidenced during a visit to Paris last month where Trump attended Bastille Day festivities. On that trip, Trump and his wife Melania dined with Macron and his wife Brigitte at the Eiffel Tower.

The Trump administration has lagged in naming ambassadors to important posts and the Republican-controlled Senate has dragged in confirming those nominees, like McCourt, who Trump has put forward, largely because of Democratic opposition.

Trump, for instance, has still not chosen an ambassador to the EU. In other cases, like Germany, the White House has identified a candidate — Richard Grenell — but Trump has not made a nomination.

The switch in posts for McCourt will likely delay her confirmation further as each ambassadorial nominee must go through a hearing before the Senate Foreign Relations Committee, where questions are posed about the specific diplomatic assignment.

Several nominees are expected to be confirmed in the next few days before the Senate leaves for its August recess, but it's still not clear how many ambassadors will be among them.