As part of a flurry of tweets Tuesday morning venting frustrations tied to Obamacare, former presidential rival Hillary Clinton and an ongoing investigation into his campaign's ties to Russia, President Donald Trump touched on trade negotiations with the United Kingdom that have largely taken a back seat during a week dominated by an upcoming health care vote.

Trump's commerce secretary, Wilbur Ross, on Monday began a two-day series of meetings in Washington with his British counterpart, Trade Secretary Liam Fox, aimed in part at laying the groundwork for an eventual trade deal once the U.K. withdraws from the European Union, which isn't expected to happen until 2019. U.S. Trade Representative Robert Lighthizer was also expected to be in attendance.

"The immediate priority is to give businesses on both sides of the Atlantic certainty and confidence. Early discussions will focus on providing commercial continuity for U.S. and U.K. businesses as the U.K. leaves the EU," Fox said in a statement. "The working group will also start to lay the groundwork for potential negotiations on an ambitious free trade agreement."

Fox's mention of a possible free trade agreement is notable, as Trump has been a vocal opponent of both the Trans-Pacific Partnership and the North American Free Trade Agreement – two free trade deals the U.S. has either previously been a part of or considered joining.

During a congressional confirmation hearing, Lighthizer indicated he believes Trump "philosophically" believes in free trade but "doesn't think that it exists right now."

Regardless, with the U.K. still not officially split from the EU, any deal taking effect between the across-the-pond allies looks to be a ways off, though Trump said Tuesday such a pact "could be very big and exciting."

Working on major Trade Deal with the United Kingdom. Could be very big & exciting. JOBS! The E.U. is very protectionist with the U.S. STOP! — Donald J. Trump (@realDonaldTrump) July 25, 2017

The U.K. was the fifth-largest buyer of American exports last year, behind only Canada, Mexico, China and Japan, according to Census Bureau statistics. The country ultimately accounted for 3 percent of all U.S. trade in 2016, buying up 3.8 percent of U.S. exports and accounting for 2.5 percent of all imports. The U.S. also maintained a slight $1.1 billion surplus with the U.K. last year.

Both the U.S. and the U.K. are vital sources of external investment for one another, and Fox has previously gone on record saying he believes trade between the two nations can ramp up even further once the U.K. is out of the EU and able to more freely set its own trade agenda.

But as the countries begin going down that path, concerns about food safety and animal welfare have arisen in the U.K., with some Parliament members fearing Fox will agree to less stringent standards to facilitate a deal with the U.S. Particularly at issue are U.S. chicken exports washed in chlorine, which don't sound particularly appealing to British regulators.

The European Food Safety Authority maintains more stringent meat and poultry standards than those in the U.S., and members of the U.K.'s House of Lords warned this week that relaxing import standards to encourage trade with the U.S. would "undermine the sustainability" of Britain's domestic agriculture industry, leaving local producers "uncompetitive" and sparking "a race to the bottom for welfare standards."

Because of the Trump administration's fixation on goods surpluses and deficits, Ross and Lighthizer are unlikely to want to rock the boat too much in terms of trade reshuffling. But with U.S. agriculture representing one of America's most significant export industries, it's also unlikely they'll skip over meat and poultry exports without a fight.