The covid crisis in Formula 1 is "much more complicated" in 2021 compared with last year, according to the sport's CEO Stefano Domenicali.
He told Auto Motor und Sport that while 2020 was all about surviving the sudden crisis, F1 must now navigate a world with highly complex new rules.
"The situation this year is much more complicated than in 2020," said the Italian.
"Last year everyone first had to find a way through the pandemic and learn. Now every country has its own rules and conditions. That is why we have to decide from day to day and remain flexible in case something changes at the last moment."
There are concerns about the viability of several races on the 23-strong 2021 calendar, with Domenicali revealing he is in "daily contact" with promoters.
"You can't imagine how much interest there is and how many tickets the promoters could sell if only they could," he said. "But of course they are dependent on the regulations of the respective governments.
"The first races are all confirmed, the question now is whether and how many spectators they can let in. At the moment we are definitely only racing in front of empty grandstands at two races - Imola and Baku.
"For all the others, the current status is about how many people are allowed to be admitted and which controls are necessary for this."
Liberty Media is only paying about 70 percent of F1's pre-covid income to teams this year, with Domenicali admitting that some of the promoters may need financial help.
"This year, a certain amount of flexibility will also be necessary," he said.
"In individual cases there may be organisers who will ask us for support. We have to find solutions for such emergencies."
