The European Council President will hold a face-to-face meeting with the British Prime Minister at 10:30am on the sidelines of a G7 summit in France, Mr Tusk's schedule showed on Wednesday.
It comes after Mr Johnson wrote a letter to Mr Tusk earlier this week, calling for the backstop to be scrapped.
Mr Johnson reiterated his opposition to the so-called insurance policy, saying he will not support any withdrawal agreement that includes it.
Responding, Mr Tusk suggested Downing Street secretly wanted to bring back a hard border with Ireland. He also said Britain was offering no “realistic” solution.
"The backstop is an insurance to avoid a hard border on the island of Ireland unless and until an alternative is found," Tusk said in a Tweet, responding to the letter on Monday.
"Those against the backstop and not proposing realistic alternatives in fact support re-establishing a border. Even if they do not admit it."
On Saturday, Mr Johnson will attend the G7 summit, where he will meet other world leaders including US President Donald Trump.
The Prime Minister is also set to meet German Chancellor Angela Merkel in Berlin on Wednesday and French President Emmanuel Macron in Paris on Thursday in his first overseas trip since entering Number 10.
The backstop is an insurance to avoid a hard border on the island of Ireland unless and until an alternative is found. Those against the backstop and not proposing realistic alternatives in fact support reestablishing a border. Even if they do not admit it.— Donald Tusk (@eucopresident)August 20, 2019
But Brussels insisted Mr Johnson would not be able to undermine the EU's unity by holding bilateral meetings with the German and French leaders.
European Commission spokeswoman Natasha Bertaud said: "The EU27 have had from the outset - and continue to have now - one single, united position on Brexit matters."
Mrs Merkel said she would use the talks with Mr Johnson to discuss how to achieve "the most friction-free British exit from the European Union possible" in order to protect economic growth.
Ireland's Foreign Minister, Simon Coveney, said a no-deal Brexit is much more likely now than it has ever been as a result of Mr Johnson's approach.
Speaking on RTE Radio One, Mr Coveney said: "There is a consequence to the approach that the British Government is taking and that consequence is that they are making a no-deal far more likely.
"There is a reason why Boris Johnson is visiting Berlin today and Paris tomorrow - to try to talk to EU leaders about finding a way forward."
"I think he will get a very consistent message from EU leaders that the negotiations over the last two to three years are not going to be abandoned now."
Tory former minister Ed Vaizey suggested Mr Johnson was "just going through the motions" with his Europe trip this week and was "hell-bent on getting no-deal".
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He told BBC Radio 4's Today programme: "We have to find a way to get Parliament to agree to a deal and therefore I would give Boris Johnson the credit of at least forcing on Parliament an existential crisis by being faced with a Prime Minister who is hell-bent on getting no-deal."
Cabinet minister Robert Jenrick said he hoped European leaders "will come to the table because it's in our mutual interest" to make the changes necessary to reach a deal before the UK leaves on October 31, with or without an agreement.
The Communities Secretary told Today: "I think the EU would be ill-advised to under-estimate our determination to do so or the degree of preparedness that we are undertaking at the moment."
Meanwhile, the Government is ramping up its preparations for no-deal with Chancellor Sajid Javid announcing an auto-enrolment scheme to help businesses prepare for post-Brexit trade with the EU.