"He's been a strong supporter of Brexit and I think he really does look forward to the opportunity to negotiate with a fully independent Britain, outside the European Union," Bolton told Sky News in London.

Bolton said the state visit will "underline the strength of the bilateral relationship."

"I think it will make it very clear that the interests and values of the United Kingdom and the United States are very, very close, regardless of political currents in either country."

Bolton said a bilateral trade deal would be good for both countries, adding, "I could imagine bringing Canada into a three-way deal in the near future."

With Prime Minister Theresa May stepping down next week after failing to get parliamentary support for her European Union withdrawal plans, a Conservative Party leadership contest is underway to succeed her. Bolton would not be drawn when asked his views on the race.