The official responsible for boosting Britain's economic relationship with North America has been appointed as the top civil servant in the trade department, as the Government seeks to reshape the country's role in the world after Brexit.
Antonia Romeo has been hired as permanent secretary at the Department for International Trade, which was set up by Theresa May in the wake of the Brexit vote.
She is currently the UK's consul general in New York and will take up the job on March 27, and base herself partly in the US until summer.
The appointment could fuel speculation that the Prime Minister will be seeking to strike a free trade deal with US President-elect Donald Trump as a priority after leaving the European Union.
International Trade Secretary Liam Fox said: "Across the world my department continues to bang the drum for the UK as an attractive place to trade and do business with, and the permanent secretary has a vital role in leading the department to deliver the UK's trade agenda at home and abroad.
"We are harnessing the very best of home-grown and international talent and I'm delighted to welcome Antonia, who brings with her extensive leadership and policy expertise that will help the UK to take advantage of the many global trading opportunities before us."
Ms Romeo said: "It is a privilege to have been appointed to lead the department as we work to promote the UK as an outward-facing, free-trading global nation.
"International trade and investment are central to UK prosperity and growth as we exit the European Union.
"I look forward to working with the Secretary of State, ministers and staff of the department as well as colleagues across Whitehall, on this challenging agenda."
Cabinet Secretary Sir Jeremy Heywood said: "I would like to congratulate Antonia on her appointment to the Department for International Trade.
"Antonia has done an excellent job in a number of roles across government and will bring a strong blend of leadership and Whitehall skills at an exciting time for the department. I am very much looking forward to working with her."
The department will also hire an international trade negotiating expert as a second permanent secretary, reporting to Ms Romeo, to "support the establishment of a world-class trade negotiation function".