File photo: Britain's Prime Minister Theresa May welcomes Ireland's Taoiseach Leo Varadkar to Downing Street in London, September 25, 2017. REUTERS/Hannah McKay

LONDON (Reuters) - Significant gaps still remain between parties attempting to restore Northern Ireland’s power-sharing administration, British Prime Minister Theresa May’s office said on Monday after she spoke with Irish counterpart Leo Varadkar.

May and Varadkar agreed in a phonecall that it was in the interests of everyone that the executive was restored, but differences remained over issues such as the Irish language. Northern Ireland has been without a devolved administration since its collapse in January, raising the prospect of direct rule being re-imposed from London.