The Italian Grand Prix saga is still not over, as the contract was not actually signed on Friday.
Bernie Ecclestone, Jean Todt and Lombardy president Roberto Maroni announced on Friday that a new three-year deal to keep F1 at Monza has been agreed.
"As soon as we agree on all the little details that are important for the contract, we will sign it in the UK," F1 supremo Ecclestone said.
"Most important is that we have finally reached an agreement and there are no more problems. The contract is for three years but I hope the race will be here for 100."
Italian automobile club chief Angelo Sticchi Damiani, who has led the negotiations, told Sky Italia: "For jurisdictional reasons it can't be signed in Italy.
"I will go to London to be sure."
Also at Friday's announcement was former Renault boss and Ecclestone confidante Flavio Briatore, who told Mediaset: "I only played the role of facilitator - those who did the negotiations did a very good job."
Monza has been the home of the Italian Grand Prix since 1950.