President Joe Biden spent Thanksgiving morning giving back to first responders on Nantucket, while also taking time to give his thoughts on his successor's threats to issue tariffs on Mexico, Canada and China.

Biden told reporters he hopes President-elect Donald Trump "rethinks" his Day 1 proposal, calling it a "counterproductive thing to do."

"We have an unusual situation in America. We're surrounded by the Pacific Ocean, the Atlantic Ocean, and the two allies: Mexico and Canada. And the last thing we need to do is screw up those relationships. I think we've got them in a good place," Biden said Thursday.

Trump said this week that he plans to sign an executive order when he takes office on Jan. 20, 2025, that would charge Mexico and Canada with a 25% tariff on all products those nations send to the United States, in an effort to stop the flow of drugs entering the country and illegal border crossings.

He also vowed to charge China with an additional 10% tariff on top of any additional tariffs on products coming into the U.S., arguing the country wasn't doing enough to stop the flow of illicit drugs.

Economists widely forecast that tariffs of this magnitude would increase prices paid by American shoppers, since importers typically pass along a share of the cost of those higher taxes to consumers.

Trump's tariffs would cost the average U.S. household about $2,600 per year, according to an estimate from the Peterson Institute for International Economics.

With migrants being the central issue for Trump in threatening tariffs, Biden noted that illegal crossings are down considerably from what they were back when Trump was in office.

"There's a lot more to do, but, I hope they reconsider," he said on Thursday.

The president noted that with a thin GOP majority in Congress, there may have to be some "real compromise" in Trump's agenda.

"I want to make sure this transition goes smoothly and all the talk of what he's going to do and not do, I think there may be a little bit of internal reckoning on his part," Biden said.

Despite the disagreements with Trump, Biden said he was thankful for his family and "for a peaceful transition," adding that he's "really thankful" to have secured a ceasefire deal between Israel and Hezbollah.

The president also said he spoke to all three Americans who were released from Chinese custody Wednesday.

"I'm happy they're home," he said.

Biden, who was joined by the first lady and his grandson Beau at a Nantucket firehouse, was asked what his message is to Americans worried about the future of the U.S. He told them to "remember who we are."

The White House said the Bidens also called units from each branch of the military "to thank them and their families for their service to the country."

Meanwhile, Vice President Kamala Harris spent Thanksgiving morning with her family at DC Central Kitchen as part of a community service project.

Harris said she will be making a turkey, her "famous corn meal stuffing," sweet potatoes, cranberry sauce, scalloped potatoes, string beans, Brussels sprouts, salad and rolls for dinner.

"Lots of carbs," she said.

When asked by a reporter, "What's next for you?" Harris joked, "Thanksgiving dinner," and continued preparing collard greens.

ABC News' Max Zahn contributed to this report.