PHOENIX (AP) — Arizona’s governor says U.S. Sen. Jon Kyl will resign at the end of the year from the U.S. Senate seat he was appointed to less than four months ago following the death of Sen. Jon McCain.

The Republican Ducey announced Friday that Kyl said he will resign effective Dec. 31.

Kyl’s departure will create another vacancy that Ducey will fill by appointment to serve until the 2020 election, when voters will pick someone to serve the final two years of McCain’s term.

Kyl had said when he was appointed that he committed only to serving until the end of this year.

Ducey’s office in a statement said Kyl submitted his resignation Thursday and that Ducey will announce his replacement “in the near future.”