'Incredible that Sinn Fein is drumming up hundreds of thousands of dollars in the US for a divisive border poll campaign'

The DUP leader, who is in the US for a series of engagements, was commenting after the ads appeared in newspapers, including the Washington Post and New York Times, on Wednesday.

He said: “Whilst some seem focused on the last 25 years, my focus is on the next 25 years.

“Over the last few days in the United States, I have focused on growing our economy and boosting jobs in Northern Ireland and bringing stability.

“Therefore I find it incredible that in newspapers across the USA this morning there is a full page advert from Sinn Fein calling for a referendum on Northern Ireland being part of the United Kingdom.”

The ads state: “The future is in the hands of the people. It is time to agree on a date for the Unity Referendums”.

Sir Jeffrey added: “Whilst I am using my time in the US to impress upon decision-makers and investors the potential of Northern Ireland, Sinn Fein is drumming up hundreds of thousands of dollars for a divisive border poll campaign.

“There is no evidence of growing support for Northern Ireland leaving the United Kingdom. Indeed, every major poll points in the opposite direction.”

The DUP leader said Northern Ireland’s future is “with unionists and nationalists working together,” and added: “A border poll would pitch unionists and nationalists against each other and lead to further divisions.

“There is no place for my unionism or my British identity in a Northern Ireland outside the United Kingdom therefore the message from Sinn Fein is not one of working together but rather one of ourselves alone.”

​Other political leaders from Northern Ireland are also in the US ahead of St Patrick’s Day.

SDLP leader Colum Eastwood has met with US Special Envoy Joe Kennedy in Washington, and afterwards said Mr Kennedy “will have an important role to play in making the most of our dual market access,” in both the EU and the UK, in terms of creating business and investment opportunities.