Ward-Prowse, who will be blogging throughout the tournament for saintsfc.co.uk, flew out to the city of Antalya with the rest of the squad this morning.
And the midfielder says that playing in the tournament will be a valuable experience at the end of his first full season as a professional with Saints.
"To be handed the chance to play at a World Cup at our age is unbelievable," James told FATV
"I think FIFA rank it as their second-most important competition so it's something that we're relishing because it's a good chance to get some experience.
"I've had a good year under my belt and I've learned a lot. I feel a lot more mature now, so I'm looking forward to contributing to this team."
Peter Taylor's men play their first group-stage fixture on Sunday 23rd June, when they take on Iraq.
Three days later they face Chile, before rounding off their Group E schedule against Egypt on 29th June.
And Ward-Prowse says he and his teammates will use the next ten days to prepare for the different styles of their three rivals, and also to acclimatise to the Turkish heat.
"From my experience of international football, different opponents throw you different things so you've got to be able to deal with them," he warned.
"Our preparation, our mentality and the way in which we apply ourselves to the matches that will prove whether we win or lose them."
Of the searing heat in Turkey, the 18-year-old added: "It's something we'll need to adapt to, and that's part of being a professional footballer.
"You need to adapt to these things if we want to play in World Cups and the Champions League for our clubs. You have to be able to deal with these conditions as well as the different things our opponents will chuck at us."
Ward-Prowse is the second-youngest member of Taylor's 21-man party, but has the highest number of Premier League appearances under his belt of the entire squad.
And he feels that the squad is bonding well under Taylor having trained together for a number of sessions at St George's Park ahead of their departure for Turkey.
"It's coming together really well," Ward-Prowse affirmed. "I know a few of the lads from the Under-19s, like John Lundstram and John Stones, so I've got a camaraderie with those boys.
"Peter Taylor has been fantastic with us and we've all bonded really well. He's had a good laugh with the lads and a really good coach, so he's someone to learn off. He offers a lot of experience for us all."
Also involved at the U20 World Cup is Saints goalkeeper Cody Cropper, who is in the final U.S. Under-20s that will be travelling to Turkey in the next few weeks.
Tab Ramos's squad are currently training in the Portuguese resort of Lagos, where they will play a friendly against Portugal Under-20s on Friday.
Cropper and his teammates recently took part in the 2013 Toulon Tournament, where they were eliminated in the group stage having played hosts France plus Colombia, Congo DR and South Korea.