Brexit talks with Brussels could run to October 31, when the UK is set to leave the EU, British Prime Minister Boris Johnson said on Monday.
But Mr Johnson repeated that Britain would depart on that date without a deal if a new withdrawal agreement were not agreed to with Brussels.
At the end of G7 talks in France, he repeatedly avoided questions of what he would do if Parliament tried to delay or block a no-deal Brexit, which critics say could send the UK into a recession.
"Well I do think that the EU does tend to come to an agreement right at the end,” Mr Johnson said.
"Clearly for us, the walking away would come on October 31 when we would take steps to come out on the terms for which we will have by then made absolutely colossal and extensive and fantastic preparations.”
Mr Johnson’s predecessor, Theresa May, stepped down after seeing the divorce deal she negotiated with the EU rejected by the UK Parliament three times.
He wants a new agreement with Brussels, but the EU says it will not renegotiate.
But Mr Johnson did receive support from US President Donald Trump.
"I really believe that Boris Johnson will be a great prime minister," Mr Trump said. "We like each other and we had a great two and a half days.
"I've been waiting for him to be prime minister for about six years. I told him, 'what took you so long?'"