Boris Johnson and U.S. President Donald Trump meet at the UN headquarters in New York on September 18, 2017

The U.K.'s priority is to strike a trade deal with the European Union ahead of the U.S., the country's Finance Minister Sajid Javid said. This came after U.S. Treasury Secretary Steven Mnuchin said that the U.S. was a "bit disappointed" not to have been able to negotiate with the U.K. first.

"In terms of our next steps on free trade, one of the big ones is with our European friends and partners, getting that new comprehensive free trade agreement where the principles have been agreed upon. That's off to a good start," Javid said Wednesday as a panelist on CNBC's 'Future of Financial Markets' panel alongside U.S. Treasury Secretary Steven Mnuchin, IMF Managing Director Kristalina Georgieva and UBS Chairman Axel Weber.

Getting a deal with the U.S. is also "a huge priority for us," he added, while noting "we've already started working closely together (toward that goal)."

Pressed on which deal was the priority, one with the U.S. or EU, Javid said, "Of course our first priority is getting the agreement with the EU."

The U.K. is due to leave the EU on Jan. 31, and the government has set a deadline for a trade deal with the EU for the end of 2020, a short time frame that many officials in Europe see as unfeasible.

While the U.K. is free to negotiate other trade deals during this "transition period" out of the EU, any other trade agreements — for example, one between the U.S. and U.K. — could only enter into force at the end of the transition period with the EU.