The Champions League 2017 final will be Cardiff's biggest event yet, the first minister has said, with 100 days to go until the city hosts the match.
World football's biggest club game will be played at Cardiff's Principality Stadium on 3 June.
Carwyn Jones told BBC Wales it was "challenging" but preparations were "going well".
"It's a going to be a great showcase for Wales," the first minister added.
Thousands of fans are expected to pour into the Welsh capital for the final, which takes place two days after the women's Champions League final at the Cardiff City Stadium on 1 June.
The 100-day countdown to the women's event was kicked off by a choir's flash mob performance in Cardiff with the trophy on Tuesday.
Wales forward Gareth Bale starred as Real Madrid beat city rivals Atletico in the 2016 final at the San Siro stadium in Milan.
And Mr Jones said it was the very fact no one yet knows who will star in this year's final which makes the planning so uncertain.
"This is the biggest [event Cardiff has hosted] to my mind, no question about that," he said.
"It's the sheer numbers of people, the sheer size of the event and the fact that we don't know who's going to be in the final so we don't know where the fans are going to come from."
He said the planners were talking to all the authorities and organisations necessary to make the event a success.
"Cardiff is the smallest city to have hosted the event. It's always challenging, of course, but we'll get there and we'll be offering a fantastic welcome to all who come to our capital city," he added.