The Trump administration says it has started laying off federal workers, as the government shutdown battle continues.

"The RIFs have begun," Russell Vought, the director of the Office of Managment and Budget, wrote on X.

RIF, which stands for "reduction in force", is a mechanism that the administration can use to lay off federal workers. The Trump administration had threatened to would use this power if the Democrats forced a government shutdown.

An OMB spokesperson confirmed the cuts had started and "are substantial" but did not provide specific number of employees set to be fired.

The facility in Idaho will be used to train Qatari pilots to fly F-15 fighter jets, the US defence secretary says.