WATCH: Mullin says he wasn't expecting call from Trump on DHS, but is 'excited to get started'

Republican Sen. Markwayne Mullin of Oklahoma is President Donald Trump's nominee for the next Homeland Security Secretary, following the firing of Kristi Noem on Thursday.

Watch Mullin's remarks in the video player above.

Trump made the announcement on social media on Thursday, two days after Noem faced a grilling on Capitol Hill from both GOP members and Democrats.

READ MORE: Trump replacing Noem as Homeland Security secretary

Mullin told reporters at the Capitol that he would get DHS "focused on protecting the homeland."

"Whether you support me or don't support me, I'm going to be laser-focused on getting that done," he added.

Mullin said he hasn't spoken with Noem after the announcement.

"I'm gonna go give her a call in just a second. Our families are very close, and this happened very quick, so we're gonna go have a conversation with her in just a second," added Mullin.

He also said that he spoke to Trump just before the announcement went out.

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