President Donald Trump’s senior adviser Wilbur Ross has said that any Brexit deal between the UK and the EU must be in the interests of the United States.

"It is ... important that an eventual Brexit agreement takes into account our commercial interests, and does not hinder development of a closer post-Brexit US-UK relationship by continuing divergent standards and regulations and other protectionist measures," said Ross on Monday.

Speaking at the annual Confederation of British Industry (CBI) conference in London, the US commerce secretary said that Britain must not compromise with the European Union if London wants to have any post-Brexit deal with Washington.

Ross said that if the UK chose to keep the EU ban on genetically modified food and chlorinated chicken, there would be problems in having “a subsequent FTA (Free Trade Agreement) with the US.”

Criticizing the EU's external trade policy, he said, "The EU talks free trade but actually is highly protectionist."

“The EU rules are not science-based,” he added, noting changing them will form a “critical component of any trade discussion” between the two countries.

UK Prime Minister Theresa May is said to have been playing up the prospects of increasing trade with “old friends” like the US and “new partners” like China, India and Japan after Brexit.

May visited Trump at the White House in January and invited him for a state visit. The two countries share $200 billion of trade each year.

The US remains the largest importer of British goods, dwarfed only by the EU as a whole. In August, for example, 14 percent of British exports were headed to the US while the EU’s 27 members imported around 50 percent collectively.

In late July, Trump announced in a tweet that he was working on a “major trade deal” with the UK.

Earlier that month, he met May on the sidelines of the G20 meeting in Germany’s Hamburg, assuring her that “trade will be a very big factor” in their “special relationship.”