Boris Johnson is to visit Berlin and Paris this week on his first foreign trips as the UK's new prime minister.
It comes amid continuing Brexit deadlock and ahead of a G7 summit this weekend.
Johnson will first head to Berlin on Wednesday to meet with German Chancellor Angela Merkel, before heading west to Paris for a meeting with French President Emmanuel Macron.
His trips come after he sent a letter to European Council President Donald Tusk on Monday in which he urged the EU to reconvene to the negotiation table and to scrap the backstop arrangement — an insurance policy to prevent a hard border in Ireland.
In lieu of the backstop, which he blasted as "unviable" and "undemocratic", Johnson instead said the UK was prepared to make other "commitments" should the two parties fail to find another solution by the end of a transition period but did not outlay what those commitments might be.
The EU has repeatedly stated that it would not reopen negotiations and that the backstop was here to stay.
It did so during Theresa May's tenure in Downing Street during which she failed three times to get parliament's approval for the Withdrawal Agreement.
Johnson may have been hoping that his pledge to take the UK out of the bloc by October 31 "do or die" — with or without a deal — would spook leaders in European capitals but he was instead rebuffed by Tusk who emphasised that the EU would champion the backstop "unless and until an alternative is found".
"Those against the backstop and not proposing realistic alternatives in fact support re-establishing a border. Even if they do not admit it," he added on Twitter.
In the German and French capitals, Johnson is unlikely to get the message to change despite Merkel's conciliatory tone on Sunday.
"We are glad of every visit, and you have to talk, and you have to find good solutions," she said.
"We are prepared for any outcome, we can say that, even if we do not get an agreement. But at all events, I will make an effort to find solutions — up until the last day of negotiations.
"I think it's better to leave with an agreement than without one. But if that's not possible, we'll be prepared for the alternative as well," she added.
Macron, meanwhile, has been one of the toughest voices on the UK during the negotiations.
In February, as the March 29 deadline was approaching, he warned that he would be against an extension unless the UK and May presented a "credible" plan to break the deadlock.
In April, as the UK was seeking a second extension which some hoped might be for another year, he lobbied for a shorter deadline arguing the bloc could no longer be "the hostage of a political crisis in the UK". It was eventually set for October 31.