Sinn Féin president Mary Lou McDonald has been criticised after she posed with a banner reading ‘England get out of Ireland’.
Ms McDonald was photographed with the banner during the New York St Patrick’s Day parade on Saturday.
Irish Tánaiste (Deputy PM) Simon Coveney described the banner as “offensive, divisive and an embarrassment”.
Sinn Féin said the criticism was “faux outrage” and “political point scoring”.
The leaders of the SDLP, Alliance and the UUP also criticised Ms McDonald.
The photo was posted on Twitter by Sinn Féin’s official account along with the caption “no explanation needed”.
Ulster Unionist leader Robin Swann called for an explanation, and said the poster was “high offensive and wrong on so many levels”.
DUP MP for East Londonderry, Gregory Campbell, said: “When slogans such as “Brits out” or “England out of Ireland” are used the unionist community are well within their rights to see themselves as the intended focus.
“Like truth and respect, explanations are demanded, but never offered by Sinn Féin.”
SDLP leader Colum Eastwood retweeted the image and said: “Sinn Féin aren’t capable of convincing unionists of anything. The rest of us will have a lot of heavy lifting to do.”
A Sinn Féin spokesperson said: “It should come as no surprise that Sinn Féin wants a new United Ireland under the provisions of Good Friday Agreement.
“The faux outrage of some of our political opponents owes more to the silly season of a holiday weekend and petty political point scoring.”
Ms McDonald was one of a number of politicians from Northern Ireland and the Republic of Ireland who were in the United States for a range of events in the run up to St Patrick’s Day.
Taoiseach (Irish Prime Minister) Leo Varadkar and Democratic Unionist Party (DUP) leader Arlene Foster were among those who travelled to the US.