Australia will host India in a multi-format series in February-March next year.
Gardner backed her side to respond strongly when they recommence their rivalry with India, the newly crowned 50-over world champions, in a multi-format series comprising three T20Is, three ODIs and a Test.
The series, slated to be held Down Under from February 15 to March 6, will mark the first meeting between the two teams since India knocked Australia out in the Women’s World Cup semi-final.
"We've certainly been put under pressure recently. But I can still sit here confidently saying that we're the best team in the world," Gardner told cricket.com.au.
Gardner also acknowledged that India will arrive on the Australian shores with momentum after a successful World Cup campaign.
"India's going to come across with a lot of confidence, as they should. They've obviously played some really good cricket recently," she added.
She cited the tightly-contested ODI series before the World Cup and India's semi-final win as proof of the challenge ahead.
Gardner, however, believes Australia will hold an edge because of familiarity with home conditions.
"They're also coming over to our conditions, which we know better than them," she said. "If they do challenge us, we know what to do in those moments as well."
Despite falling short in recent ICC events, Gardner emphasized Australia's consistency over the past year.
"Over the last 12 to 18 months, we've only lost about two games, and I think the two games that we lost were both in semi-finals," she said.
"It kind of shows the consistency of the group. It's just about putting those pieces together to hopefully win those trophies."
Gardner pointed out execution in pressure moments as a key area for improvement. "Just winning those small moments in those high-pressure situations, which ultimately in a World Cup, when you're playing finals cricket, you need to be able to do, and for us, we weren't able to do that," she said.
Gardner also highlighted the importance of mental clarity to excel in pressure situations. "Sometimes when you're under pressure, maybe you make the wrong decision," she said. "It's making sure that we know the mental side of our game is in the best place it can be, because ultimately that's going to help you make the right decision on the field."