LONDON — U.S. national security adviser John Bolton said Monday that the White House fully supports British Prime Minister Boris Johnson’s plans to leave the European Union by Oct. 31, even without a Brexit deal.

“I think if that’s the decision of the British government, we will support it enthusiastically,” Bolton said. “And that’s what I’m trying to convey: We’re with you. We’re with you.”

Bolton, speaking to reporters in London after a day of meetings with British officials, said it was “unmistakable” that the United Kingdom will be exiting, whether the new government reaches a deal with the E.U. or not. "They’re ready to go,” Bolton said.

He said the White House agreed to put discussions on issues unrelated to Brexit on hold while the British government focuses on leaving the bloc, including whether the U.K. will stick with the Iran nuclear deal or declare it dead as the United States hopes.

“The president and the U.S. government fully understand that in the next 80 days, the U.K. government has a singular focus on the Brexit issue,” he said. “We just ask that as issues come up, we just resolve them individually and that we reserve the time to have a larger conversation on some of these important issues at a moment that’s really right for the new government.”

Bolton spoke with Johnson for a few minutes Monday while he was at 10 Downing Street meeting with some of his top advisers. They discussed Brexit and Johnson’s planned first meeting with President Donald Trump since he became prime minister, set to take place later this month on the sidelines of the G-7 Summit in France, Bolton said.

The relationship between Trump and Johnson is “off to a roaring start,” Bolton said, and they’ve already had a handful of phone calls.

Trump and Johnson spoke again Monday about trade and global security issues, according to the White House.

“The president expressed his appreciation for the United Kingdom’s steadfast partnership in addressing global challenges and looks forward to meeting with him personally in the near future,” White House spokesman Judd Deere said in a statement.

A Downing Street spokesperson said Johnson and Bolton discussed trade between the U.S. and the U.K., “and our shared commitment to an ambitious free trade agreement once the U.K. leaves the E.U.”

“They also spoke about Brexit and a range of other issues — including Iran, Hong Kong, and 5G,” the official said.

Bolton, who predicted that Brexit “will result in a strong NATO,” is scheduled to meet with defense and trade ministers here Tuesday.

He said the main focus in the U.S.-U.K. relationship right now is negotiating bilateral trade agreements that would initially deal with specific sectors, perhaps financial services and some manufactured goods, then shift to a more comprehensive deal. The goal is to achieve “as much as we can agree on as rapidly as possible,” Bolton said.

Bolton predicted that any new U.S. trade agreements with the U.K. would receive overwhelming bipartisan support in Congress.

He said there is “zero chance” that Brexit would pose a threat to the Good Friday agreement, a peace accord between the Republic of Ireland and Northern Ireland. Some U.S. lawmakers have expressed concern that Brexit without an agreement with the E.U. would jeopardize the peace deal by closing off the open border between Ireland and Northern Ireland.

“Nobody in Britain or anywhere else has talked about a hard border with the Republic of Ireland. That’s in nobody’s interest,” Bolton said. If there’s no Brexit deal with the E.U., then there won’t be a backstop resolution, he said, but the U.K. and Ireland will figure out how to resolve the issue.

“The administration remains a strong supporter of the Good Friday agreement and we don’t see what the threat is,” Bolton said.

While Bolton said he and British officials discussed Britain’s use of equipment from the Chinese telecommunications company Huawei, which the Trump administration has said is a national security threat, the U.K. is not going to make any decisions on the issue until after Brexit.

Even though the Johnson government will try for a Brexit deal with the E.U., Bolton gave no indication that the White House anticipates there will be an agreement. In that instance, he stressed the Trump administration will work with the U.K. to help achieve a smooth exit. He forcefully backed Britain following through this fall with the June 2016 vote to leave.

“The issue was leave or remain, and they voted to leave,” Bolton said of U.K. voters. “The fashion in the European Union: when the people vote the wrong way from the way the elites want to go, it’s to make the peasants vote again and again until they get it right.”