Hillary Clinton addresses the Northern Ireland Assembly.

Hillary Clinton arrives in a motorcade at Stormont Castle.

Peter Robinson, Hillary Clinton and Martin McGuinness at Stormont Castle.

Hillary Clinton is driven to Stormont Castle in Belfast.

Hillary Clinton, with Peter Robinson and Martin McGuinness, at Stormont Castle in Belfast.

Hillary Clinton meets Willie Hay, the Speaker of the Northern Ireland Assembly at Stormont Castle in Belfast.

Hillary Clinton addresses the Northern Ireland Assembly.

Hillary Clinton leaves Stormont.

Hillary Clinton, with Peter Robinson and Martin McGuinness, at Stormont Castle in Belfast.

US Secretary of State Hillary Clinton and Belfast Lord Mayor Naomi Long speaking before Mrs Clinton unveiled a plaque at the official reopening of Belfast City Hall.