Captain Gareth Bale said Wales are desperate to qualify for their first World Cup finals appearance in 64 years when they take on Ukraine in Sunday's playoff match at the Cardiff City Stadium.
Wales' only World Cup finals appearance was in Sweden in 1958, where they lost to Brazil in the quarterfinals.
"It's a big game. It's difficult to put it into whether it's 'the' big game. Obviously, we played in a semifinal of a European Championship" in 2016, Bale, who sat out Wales' 2-1 Nations League defeat to Poland, told reporters on Saturday.
"It's a massive game. I think there's no hiding it. We've only played in one World Cup.
"So this is a stepping stone that all of us want to take to play on the biggest level. And yeah, we have a massive game tomorrow that we're desperate to win and to achieve our goal."
Most neutral viewers will likely be supporting Ukraine in the wake of Russia's invasion of their country, which Moscow calls a "special military operation."
When asked how it felt to be taking on Ukraine in such circumstances, Bale said the most important thing was that Wales would be "the most popular team in the stadium."
"Everyone in the world feels for Ukraine," Bale said. "It is sport that unites everybody. We understand what it will do for Ukraine, but we want to get to the World Cup.
"That is not coming from a horrible place. It is coming from our country and hearts as we want to deliver for our own fans."
Soccer's global showpiece event in Qatar will be held from November 21 to December 18.