LONDON, Dec 21 (Reuters) - British supermarket group Iceland has experienced strong trading that is ahead of its expectations as the Omicron variant of coronavirus has spread across the United Kingdom and hit the hospitality industry, its managing director said on Tuesday. "Sales are actually really quite strong, we"ve had a good couple of weeks and we"re ahead of budget," Richard Walker told Sky News. But he added that the increase in infections was starting to impact the level of staff absences.