After months of build-up and speculation, Democratic nominee Joe Biden has officially picked his running mate.

The former vice president declared that he has selected California Democratic Sen. Kamala Harris.

Biden and Harris appeared together for the first time as running mates Wednesday afternoon in Wilmington, Delaware.

Biden made a bizarre comment about Harris will be ready to take over on Day 1 -- which lends credence to claims that she will be running the Oval Office, not him, if they win in November.

"She's a proven fighter," Biden said. "She's ready to do this job on Day One." 

"The choice we make this November is going to decide the future of America for a very, very long time," Biden said. "I have no doubt that I picked the right person to join me as the next vice president of the United States of America, and that's Senator Kamala Harris."

"This morning, all across the nation, little girls woke up, especially little Black and brown girls, who so often feel overlooked and undervalued in their communities," Biden continued. "But today -- today, just maybe, they're seeing themselves for the first time in a new way -- as the stuff of president and vice presidents."

"When I agreed to serve as President Obama's running mate he asked me a number of questions, as I've asked Kamala. The most important one was, he said to me, he asked me what I wanted, most importantly. I told him I wanted to be the last person in the room before he made the important decisions," Biden said.

"That's what I asked Kamala. I asked Kamala to be the last voice in the room, to always tell me the truth, which she will. Challenge my assumptions if she disagrees. Ask the hard questions. Because that's the way we make the best decisions for the American people," he continued.

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Harris then spoke about when Biden called her with the news and how she is also "ready."

"As I said, Joe, when you called me, I am incredibly honored by this responsibility and I'm ready to get to work," Harris said.

"Joe, I'm so proud to stand with you. And I do so mindful of all the heroic and ambitious women before me whose sacrifice, determination, and resilience makes my presence here today even possible," she continued.

"America is crying out for leadership," she said, "yet we have a president who cares more about himself than the people who elected him."