Youth Olympic champions Kagiyama Yuma (junior men) and Apollinariia Panfilova/Dmitry Rylov (junior pairs) also set to compete in Tallinn.
The pair, who dueled it out at the Junior Grand Prix Final in Turin where Liu finished second to Valieva in her only defeat of the season, are the top billing among the 48 skaters from 41 countries competing in the Junior Ladies event.
It will be the World Juniors debut for both skaters, who are still just 14 and 13 respectively.
Both girls have quadruple jumps in their repertoires, making the contest an intriguing one to watch.
Valieva, who is able to land a quadruple toe loop, doesn't have a quad jump listed, although that does not mean she won't perform one when the time comes.
Liu, the two-time senior American champion, is also capable of jumping the triple Axel, a jump she has listed in both of her planned programs in the Estonian capital.
However, speaking to the International Figure Skating Magazine, she played down expectations of perfection.
"I don’t expect to be perfect … there are obviously going to be mistakes, but I can learn from them," she said.
"I would be happy with any podium placement."
Japan's Kagiyama will face competition from 34 other skaters representing 28 countries in his event.
The biggest challenge appears to be from the Lausanne silver medallist Andrei Mozalev of Russia, while other names like Daniel Grassl of Italy – last year's world junior bronze medallist, and Junior Grand Prix Final champion Sato Shun, will also figure in contention.
Meanwhile, Panfilova and Rylov are one of 16 pairs from 10 countries taking part, including Lausanne bronze medallists Alina Butaeva and Luka Berulava of Georgia and team silver medallists Cate Fleming and Jedidiah Isbell from USA.
In the Junior Ice Dance, Lausanne 2020 bronze medallists Katarina Wolfkostin and Jeffrey Chen (USA), team gold medallists Yoshida Utana and Nishiyama Shingo (Japan), and team bronze medallists Natalie D'Alessandro and Bruce Waddell all feature. Junior Grand Prix Final champions Maria Kazakova and Georgy Reviya are also likely to provide stiff competition. There are 29 ice dance couples representing 22 countries in Estonia.
Tickets to the event cost five to seven euros (U.S. $5.50 to $7.80) per day, or 30 to 40 euros (U.S. $33 to 45) for a whole-event ticket.
All skaters and staff members are to be screened by medical staff, in light of the current coronavirus outbreak.
The event will take place over seven days, with four days of competition. Practice will take place every day from 2 March. (All times below are Tallinn local time, which is UTC +2 hours.)
Wednesday 4 March
11:15 Junior Men short program
18:30 Opening ceremony
19:15 Junior Pairs short program
Thursday 5 March
12:30 Junior Ice Dance rhythm dance
18:30 Junior Pairs free program and victory ceremony
Friday 6 March
10:15 Junior Ladies short program
18:15 Junior Men free program and victory ceremony
Saturday 7 March
11:45 Junior Ice Dance free dance and victory ceremony
15:45 Junior Ladies free program and victory ceremony
Sunday 8 March
15:00 Exhibition gala