Marco Rubio waves to supporters during a watch party at the Downtown Marriott Hotel in Des Moines. (Dave Kaup/Reuters)

MANCHESTER, N.H. — Fresh off a surprisingly strong third-place showing in the Iowa caucuses, Sen. Marco Rubio hit the campaign trail in New Hampshire early Tuesday morning, stopping at a local diner where he mingled with voters, did a round of TV interviews and voiced confidence about his chances in the first-in-the-nation primary state.

Rubio (R-Fla.) also attracted the attention of some supporters of Democratic presidential candidate Sen. Bernie Sanders (Vt.), one of whom tried to ask a question about nuclear weapons but was discouraged by Rubio's staff.

The retail stop was the first in what promises to be a busy week in New Hampshire for Rubio, who picked up momentum in Iowa by finishing just behind runner-up Donald Trump and not far behind the winner, Sen. Ted Cruz (Tex.).

“Turnout was massive,” Rubio said of Iowa as he made his way through the Airport Diner. Later, he added, “I got more votes than Santorum did, than Romney did, than Huckabee did," listing the names of top finishers in 2012 and 2008.

One customer presented Rubio with some cigars. Rubio responded playfully: “Let's hide them, guys. I used to smoke a little cigar here and there. Now it’s just hard to do.”

"I don’t want the kids to see. And no one will know, right?” he added, jokingly hinting at the pack of reporters surrounding him.

“Maybe we’ll save them for Tuesday night,” he concluded. His supporters cheered that comment.

Seated in one booth was a trio of Sanders supporters. One of them, a young woman, told a reporter before Rubio arrived that she wanted to ask the senator a question about nuclear weapons. As Rubio made his way around the diner, she rose to try to engage with him. But Rubio staffers asked that she instead let him continue his retail campaigning and said that he would have time after his next event. “But I have done this with other candidates” -- including Wisconsin Gov. Scott Walker, who suspended his campaign last year -- she protested, appearing annoyed at the resistance.

As Rubio circled back through the diner, he acknowledged the woman and her group. “Let me say hi to these people,” he said. A staffer hinted at Rubio not to engage. “I’ll see you guys in a second,” he said as he walked to a camera to do an interview with Fox News.

“Quick question," the woman said, trying to get a word in.

After the Fox interview, the woman and her party had left. Rubio exited out a back door after an interview with a local TV station.

Rubio said he was "glad to be back" in New Hampshire. Two supporters held up homemade signs supporting him. "No more waiting!!!" read one. "We have your back in NH," said another.

“How do you feel?” a reporter asked Rubio as he made his way out.

“Very good,” he responded.