A Derry woman who is challenging a requirement that she renounce her British citizenship before she can legally identify as Irish has met former US secretary of state Hillary Clinton.

Emma DeSouza took her citizenship campaign to the United States to highlight what she describes as the British government's failure to give domestic legal effect to the birthright provisions of the Good Friday Agreement.

Ms DeSouza is challenging being automatically determined to be a British citizen under UK law rather than having a choice of Irish citizenship.

Last October, an immigration tribunal ruled that the people of Northern Ireland remain British citizens even if they identify as Irish.

At the end of a week-long visit to the US, Emma DeSouza met Mrs Clinton to discuss her case.

"We held a lengthy discussion on the importance of protecting the identity and citizenship provisions of the Good Friday Agreement and ensuring that the Good Friday Agreement is adhered to in domestic UK policy and practice," Ms DeSouza said.

Last week she met members of the US Congress on Capitol Hill, including Congressman Richard Neal, chair of the powerful Ways and Means Committee, Congressman Brendan Boyle, and Republican Congressman Peter King.

While in Washington, Ms DeSouza also met the Irish Ambassador to the US Dan Mulhall and members of the Ad Hoc Committee to Protect the Good Friday Agreement.

"The response from Congressional leaders and Irish America serves as a reminder of the enduring support of the United States for the peace process," she said.