A Downing Street spokesperson said:

The Prime Minister telephoned Arlene Foster today, following the Northern Ireland elections. The Prime Minister congratulated Arlene Foster on her re-election and they spoke about the importance of maintaining a strong and stable devolved administration in Northern Ireland.

The Prime Minister also telephoned Martin McGuinness to congratulate him on his re-election, and reiterate his commitment to work closely with him, and the new Executive when it is formed.