BERLIN — British Prime Minister Boris Johnson begins his high-stakes European tour Wednesday by traveling to Germany for meetings with Chancellor Angela Merkel as he seeks to persuade the European Union to reopen talks on Brexit.

The meeting comes as positions on Britain's divorce from the EU have hardened on both sides of the English Channel, hurtling Britain toward a no-deal exit that would damage both economies. The EU refuses to renegotiate the deal it hammered out with Johnson's predecessor. But his office says "there's no prospect of a deal" unless the EU scraps controversial language designed to prevent the return of border checks on the Irish border but could leave Britain tied to the bloc indefinitely.

"I think it's a bit paradoxical that the EU side is talking about us putting up all the barriers. We've made it clear 1,000 times we don't want to see any checks on the Northern Irish frontier at all," Johnson told ITV. "By contrast, it is the EU who currently claim that the single market and the plurality of the single market require them to have such checks. I don't think that's true."

After meeting with Merkel, Johnson goes on to Paris on Thursday for talks with French President Emmanuel Macron. His travels end at a three-day summit of G-7 leaders, including U.S. President Donald Trump, which begins Saturday in Biarritz, France.

Johnson formally delivered his Brexit demands to the EU on Monday, saying the Irish border backstop must be scrapped and replaced with "alternative arrangements" to regulate cross-border trade. In the past, border checkpoints between EU member Ireland and U.K. member Northern Ireland have been a flashpoint for sectarian violence.

In a letter to Donald Tusk, president of the European Council, Johnson said the Irish backstop was "anti-democratic and inconsistent with the sovereignty of the U.K." because it would impose EU trade rules on Northern Ireland, creating a regulatory border between the province and the rest of the United Kingdom.

Johnson said the backstop also threatens the peace process in Northern Ireland because it would give control of large parts of the economic and commercial life of the province to an external body, thus "weakening the delicate balance" between rival factions.

Tusk responded with a ringing defense of the backstop.

"Those against the backstop, and not proposing realistic alternatives, in fact support reestablishing a border," Tusk tweeted Tuesday. "Even if they do not admit it."

Merkel sounded more diplomatic, but stuck to the substance of the EU line. The German leader said the remaining 27 EU countries are willing to find a solution to the Irish question but don't want to reopen the carefully negotiated Brexit deal.

Former British Prime Minister Theresa May negotiated the withdrawal agreement with the EU, but it was rejected by the U.K. Parliament three times. Johnson, who has long campaigned for Britain to take a tougher line with the EU, replaced May as prime minister last month.

Since taking office, Johnson has said that he wants to reach agreement with the EU but that Britain will leave the bloc on Oct. 31 even if no deal can be reached. Holding out the possibility of a no-deal Brexit is the only way to force the EU to negotiate, he says.

"He's (Johnson) saying ... he will negotiate energetically in the pursuit of a deal, he's very happy to sit down and to talk to EU leaders, but he's making clear that the backstop needs to be removed," Robert Jenrick, a British cabinet minister, told the BBC on Wednesday. "That is the only prospect of securing a deal."

The withdrawal agreement is just the first step in Britain's exit from the EU and will be followed by likely years of negotiations on future relations. In addition to the withdrawal agreement, May's government agreed to a "political declaration" that spells out goals for close cooperation on trade, immigration and regulatory matters.

Thomas Matussek, a former German ambassador to the U.K., said Merkel is likely to offer concessions on the political declaration, but she can't compromise on the "four freedoms" that underpin EU institutions: the free movement of people, goods, services and capital.

The backstop is designed to protect the integrity of the European single market while ensuring that there is no hard border between Northern Ireland and the Republic of Ireland.

“We cannot throw Ireland under the bus,” Matussek told the BBC. “What message would that send to other members of the EU family if we gave up that sort of loyalty and solidarity?”