"Mr. Tusk said Mr. Johnson risked being remembered as "Mr. No Deal" - but the PM responded by saying it was Mr. Tusk who would become "Mr. No-Deal Brexit," the BBC informs.
Donald Tusk said that Brussels "was ready to listen" to PM's Brexit ideas provided they were "realistic".
But speaking at his press conference in Biarritz, the President of the European Council said he would "not co-operate on no-deal".
The officials should meet on the G7 Summit for the further negotiations on Sunday in France.
As Johnson has become the Prime Minister, he claimed Great Britain would leave the European Union until October 31 with or without the deal.
Boris Johnson has repeatedly stated he would prefer to leave the EU with a deal, but insists the backstop, the insurance policy designed to avoid a hard border on the island of Ireland must be removed from the withdrawal agreement.
"The EU has always been open to co-operation. One thing I will not co-operate on is a no deal," Donald Tusk said during his press conference.