David Cameron was asked about the death of David Phillips in Wirral by ITV News at the Conservative Party conference in Manchester.
Watch live as England hold a press conference following this weekend's Rugby World Cup exit.
The hosts crashed out after Saturday's defeat to Australia at Twickenham, but have one remaining game to play in the tournament's group stages.
The press conference is due to take place at 5pm, with coach Andy Farrell among those speaking.
Nato has told Russia to immediately stop its attacks on Syrian rebels and civilians and instead focus its efforts on fighting Islamic State.
The alliance also called on the Russians to "cease and desist" what it described as an "irresponsible" and dangerous violation of Turkish airspace during strikes.
The statement from Nato ambassadors followed an emergency meeting in Brussels on the situation.