Northern Ireland First Minister Peter Robinson has said he is stepping aside because of an impasse that threatens to bring down the Catholic-Protestant power-sharing government.

Robinson said today that all but one of his party's ministers will step down immediately, gravely weakening the coalition government that is a cornerstone of the 1998 peace agreement.

He said he was leaving Arlene Foster in place as a temporary first minister and finance minister to prevent other parties from taking advantage of the situation.

Robinson said crisis talks with the government will continue.