Nigel Farage says there needs to be "some kind of alliance" between the Tories and the Brexit Party for the upcoming election.
Reports have suggested Mr Farage's party would stand down hundreds of election candidates for December's poll to stop a split in the pro-Brexit vote.
The Conservatives have consistently ruled out a formal pact with the party.
It comes after President Donald Trump said Mr Farage and Boris Johnson should team up as "an unstoppable force".
The Brexit Party's launch for its official election campaign has just begun and Mr Farage is expected to announce the party's strategy.
Chairman of the party, Richard Tice, said: "We have a major role to play in the outcome of this general election."
The Brexit Party's MEP for the North West of England, Claire Fox, said she was "really excited by this election because voters can take centre stage again".
In August, Mr Farage tweeted the party had "635 men and women from all walks of life who are prepared to fight a general election".
And in September, the party issued a list of 409 candidates standing in England, Scotland and Wales.
Mr Farage has been critical of Mr Johnson's failure to deliver on his promise that the UK would leave the EU on 31 October.
But earlier this week, the Telegraph reported the Brexit Party was considering removing candidates to help the Conservatives win a majority of seats in 12 December's election to ensure the UK leaves the EU.
Instead, it said, they would focus their energies on Labour-held seats which voted Leave in the 2016 EU referendum.
Mr Farage called the reports "idle speculation".
But speaking about his party's launch on Friday morning, he told LBC radio: "Most of what I will be saying will be about Boris' deal and the need, in my view, for some kind of alliance."
He refused to comment on whether the Brexit Party would be fielding "20 or 200 candidates".
On the other side of the Brexit debate, Remain-supporting parties have been negotiating electoral pacts in certain constituencies.
The potential agreements would see the Liberal Democrats, Greens and Plaid Cymru stand aside for each other to ensure the election of as many MPs who back a second Brexit referendum as possible.
Green Party co-leader Jonathan Bartley said it was "no secret" that the his party was "talking to the Lib Dems and Plaid" but "nothing has been finalised".