Playing in his fourth World Cup, Xhaka said the Swiss were confident and "yearning for it like never before", and will go all out for victory against the back-to-back Asian champions in Santa Clara on Saturday.
"In football we always talk about tactical things, but you also have to enjoy the moment and I think this is one of the most important things in football, that you go on the pitch, that you feel free," Xhaka told a press conference.
"We just want to bring our 'A' game tomorrow. We will want to perform for Switzerland, for our families. Tomorrow we will take the first big step. This is going to be the best World Cup.
"We are now impatient," he added. "We are primed and ready. We are physically ready, we are mentally ready."
Switzerland are playing in their sixth successive World Cup, a feat matched only in Europe by France, Spain, England, Portugal and Germany.
But unlike those sides, the Swiss have little to show for it, with round-of-16 exits in five of their past six appearances, with their last quarter-final back in 1954.
A win against Qatar would put them top of Group B ahead of Bosnia and co-hosts Canada, who drew 1-1 on Friday.
Lessons learned from past World Cup
Xhaka, 33, is the fulcrum of Swizerland's team and the country's most capped player.
He is expected to pass the 150 cap mark at the World Cup and on Saturday, he and defender Ricardo Rodriguez will, if selected, both set a national record of 13 appearances in the tournament.
Coach Murat Yakin said his current squad have what it takes to do well at the World Cup and his aim is to take the game to Qatar early on.
He said his squad, 17 members of which were at the last World Cup, had learned a lot from that tournament, which they exited in the last 16 with a 6-1 hammering by Portugal.
"Two thirds of the players of my team have already played in a big tournament," Yakin said. "We learned our lessons from the past. Now, four years later, we have more experience. We do things better."
The 2026 World Cup will be held from June 11th to July 19th in the United States, Canada and Mexico. The tournament will feature 48 national teams and will be played in 16 modern stadiums.
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