Exhibit 23.3

Consent of Independent Registered Public Accounting Firm

NioCorp Developments Ltd.

Centennial, Colorado

We hereby consent to the incorporation by reference in the Prospectus constituting a part of this Registration Statement of our report dated October 6, 2023 relating to the consolidated financial statements of NioCorp Developments Ltd., appearing in the Company’s Annual Report on Form 10-K for the year ended June 30, 2023. Our report contains an explanatory paragraph regarding the Company’s ability to continue as a going concern.

We also consent to the reference to us under the caption “Experts” in the Prospectus.

/s/ BDO USA, P.C. 

Spokane, Washington

October 13, 2023