The Saudi Arabian Grand Prix is "up against it" to complete the Jeddah facility set to host the country's first Formula One race on Dec. 5.
Photos have emerged in the past week showing the facility far from completed in terms of both the circuit and the paddock and pit complex, raising concerns the venue will not be ready in time.
FIA race director Michael Masi is visiting the circuit on Tuesday to inspect and give the track formal sign off to host the race.
F1 is sticking to the line that the race will be ready to host the penultimate round of the championship, although sporting director Steve Nielsen, one of the key figures in bringing new facilities to the calendar, has said there's still a lot that needs doing.
"It's an ambitious project, it will be a great facility," Nielsen told Autosport.
"They're up against it, they are. But they're literally working 24/7 as they have been for quite a long time now. I saw some more photos this morning, and they've made huge progress. But still a lot to do.
"So it really is going to be down to the wire. But they'll get it done. Everything we need to put the race on safely we'll have, I'm confident of that."
After Sunday's Brazilian Grand Prix, Masi said: "I'm confident that it will be ready.
"It was always going to be very close. There's no doubt about that.
"Everything that I've seen, the progress day-on-day and week-on-week has been amazing since I was there last. Looking forward to having a look Tuesday."