International Olympic Committee president Jacques Rogge visited the Olympic Park and told London 2012 that they must "work hard".
But he was not worried about the austerity measures, including £27 million in cuts demanded by Britain's new Government, saying the budget for the Olympic Delivery Authority (ODA) which is in charge of build and infastructure is "lean" but "sound".
Mr Rogge was in London as the IOC's co-ordination commission of inspectors begins a regular three-day check-up of preparations for the London 2012 Games.
He was impressed that work on the showpiece stadium was "so far advanced".
His tour of the Olympic Park in Stratford, east London, where more than 65 per cent of the venue is already Games-ready, also included a look at the athletes' village.
"I think the budget of the ODA, including the cuts by the Government of £27 million, is a sound budget... We are at a point where every pound has to be very well spent."