After 2016 presidential candidate Scott Walker backed out of a scheduled speech at this weekend’s California Republican Party (CRP) Convention in Anaheim, California, former Ambassador John Bolton stepped in to fill the gap.

A statement from the CRP indicated that Walker withdrew from the commitment to “focus his efforts on the early primary states.”

In a message to convention delegates, California Republican Party Chairman Jim Brulte wrote, “We would like to thank Ambassador Bolton for agreeing to speak at the Saturday Dinner Banquet on such short notice, and share our appreciation to former CRP Chairman Ron Nehring for his help in arranging the ambassador’s participation.”

2016 GOP presidential candidates will be convening at the Ronald Reagan Presidential Library in nearby Simi Valley, California, on Wednesday, September 16 for the highly anticipated CNN/Salem Communications GOP presidential primary debate.

Former Governor Mike Huckabee, also a 2016 presidential candidate, will speak Friday at the CRP convention.

Walker’s position in GOP presidential rankings has been slipping, as noted in Breitbart News on the candidate pulling out of the convention.

“During the Obama presidency America has failed to lead and we are more vulnerable now than ever before,” said Bolton in a Monday statement, adding,

From the Iran deal to China and Russia, we need to change the direction of America’s foreign policy. On Saturday, I’m looking forward to speaking at the CRP convention. It’s important to continue the discussion on national security following the Republican debate at the Reagan Library.

Brulte noted Bolton’s service from 2005-2006 as U.S. ambassador to the United Nations in his Monday email and the four years Bolton served as under-secretary of State for Arms Control and International Security.

Brulte said in a Monday statement from the CRP, “With Ambassador Bolton’s experience in foreign policy and national security, I’m looking forward to hearing his thoughts on the important international issues facing America today.”

Follow Michelle Moons on Twitter @MichelleDiana.