Jagr had announced his retirement from international play after the 2015 IIHF World Championship in Prague, Czech Republic, but there was hope he would come back for this best-on-best tournament in North America, especially because it could be used as preparation for the 2016-17 NHL season.
The tournament runs from Sept. 17 to Oct. 1 in Toronto and coincides with the start of NHL training camps.
The Czech team will wait as long as necessary for the opportunity to add one of the greatest players in NHL history and an icon of the Czech national team.
"We'll give him some time," coach Josef Jandac said. "He is still one of our best players. We're going to wait for his decision."
"I was in the Olympics," Czech forward Ondrej Palat said after Tampa Bay Lightning practice in Ottawa, "so I had that experience with [Jaromir] Jagr, [Jakub] Voracek, [Marek] Zidlicky, those big names in Czech hockey. It was a good experience and I think everybody hopes Jagr will say yes at the end, because he's having a really good season and he's still an awesome player, so I think the whole Czech Republic is just hoping he will say yes."
Jagr, 44, is the leading scorer for the Florida Panthers this season with 21 goals and 47 points in 60 games.
He has 1,849 career points, in 1,610 NHL games, one point behind tying Gordie Howe for third place on the NHL all-time list.
Jagr scored his 742nd NHL goal on Feb. 20 to pass Brett Hull for third place on that list. He trails Howe (1,850), Mark Messier (1,887) and Gretzky (2,857) in points.