Scotland's First Minister said she would take on Boris Johnson and Jeremy Corbyn "anywhere, anytime".
Her comments came after Liberal Democrat leader Jo Swinson complained to broadcaster ITV about its decision to exclude her from debates, with Mr Johnson and Mr Corbyn set to go head-to-head on the channel.
When asked if she would like to be included in the TV debates, the SNP leader said she "absolutely" would.
Ms Sturgeon spoke during a campaign visit to a chemist in Rutherglen, South Lanarkshire, where she was joined by local candidate Margaret Ferrier.
She said: "My message to Jeremy Corbyn and Boris Johnson is: 'What are you scared of?'
"I'll debate one of them, I'll debate both of them, anytime, anywhere.
"Bring it on, stop running scared of meaningful debate in this election. The people can see you."
The First Minister, who also paid a visit to a nearby cafe with Ms Ferrier, warned broadcasters against "going back in time" by only inviting the leaders of the two largest parties to the debate.
Ms Sturgeon said: "The population, certainly in Scotland, but across the rest of the UK, is moving away from the two-party system.
"You've got the broadcasters not only sticking to that but actually going back the way, because in 2010, 2015 and 2017 they had a different approach to that.
"My message to the broadcaster is make sure that you're reflecting politics as it is and not just how you want it to be."
During the third leg of her day on the campaign trail, Ms Sturgeon joined in with Scottish country dancing at Lochside Community Centre in Dumfries with SNP candidate Richard Arkless.
Speaking after the dance, Ms Sturgeon reiterated her claim Boris Johnson would include the NHS in post-Brexit trade negotiations with US President Donald Trump.
Calling for the election to usher in the end of austerity, which she described as "the biggest danger to our NHS over the last few years", Ms Sturgeon said: "We want guarantees that our NHS will be protected.
"There is a risk to the NHS in this election - if we allow Scotland to be taken out of Europe against our will, which is what this broken Westminster system threatens to do - we put our NHS at the mercy of Donald Trump in future trade negotiations.
"Despite the denials of Boris Johnson, whose word hasn't shown to have been particularly trustworthy since he became Prime Minister, that in my view is a real and present danger."