British Foreign Secretary Boris Johnson, left, and U.S. Secretary of State John F. Kerry attend a news conference in London on July 19. (Kirsty Wigglesworth/AFP/Getty Images)

Secretary of State John F. Kerry on Tuesday offered praise and a primer on diplomacy to Boris Johnson, Britain’s foreign secretary, whose reputation for gaffes and insults precedes him.

When the two appeared before reporters after a brief meeting in Johnson’s office, Kerry said the U.S. ambassador to the European Union had just been regaling him with tales of his experiences with Johnson while they were at Oxford University together.

“He told me this man is a very smart and capable man,” Kerry said. “That’s the Boris Johnson that I intend to work with, and we intend to make good things happen.”

Johnson, standing with Kerry at twin lecterns, uncrossed his arms and adopted a look of modesty, interjecting: “Phew. Just stop that.”

Then Kerry sidled closer to Johnson and told him, with a wry smile, “It’s called diplomacy.”

As the exchange illustrated, the first bilateral meeting between Kerry and Johnson and the latter’s first news conference as foreign secretary was a friendly but occasionally awkward affair.

Their approaches could not be more different. Johnson, with his messy blond hair, made his opening remarks from notes. The tall and silver-coiffed Kerry spoke mostly extemporaneously, an experienced hand at answering questions.

At times, Kerry sounded like an instructor to the neophyte diplomat. He went out of his way to recite a long, sober list of crises and challenges before them, including the war in Syria, international terrorism and complex trade deals.

He gave the impression that he was addressing Johnson as much as the world, almost as if he were trying to exhort his counterpart to act less like Shakespeare’s wayward Prince Hal and more like the responsible and capable Henry V.

Johnson’s initial forays into international politics — a meeting Monday with E.U. officials in Brussels and talks Tuesday in London with Kerry and European diplomats on Syria and Yemen — are viewed as a partial charm offensive. Everywhere he goes, he is trying to undo the damage wrought by his previous verbal excesses.

Those mocking remarks continue to dog Johnson. He said last week that the United States will be “in the front of the queue” for an apology from him, after earlier saying that President Obama’s “part-Kenyan” heritage gives him an “ancestral dislike of the British Empire.” He also has compared Hillary Clinton, the presumptive Democratic presidential nominee, to “a sadistic nurse in a mental hospital.”

Johnson bristled when asked whether he wanted to take back his remarks about Obama and Clinton.

“I am afraid there is such a rich thesaurus of things that I have said that have been, one way or another, through what alchemy I do not know, somehow misconstrued, that it would really take me too long to engage in a full global itinerary of apology to all concerned,” he said. “I think most people who read these things in their proper context can see exactly what was intended. Everybody I’ve met in the job so far understands that, particularly on the international scene.”

Kerry, who winced when a ­reporter spoke of Johnson’s “outright lies,” seemed unsure how to respond when asked whether he had met anyone like Johnson before. “With respect to my colleague now,” he started, “let me say, I served 28 years in the United States Senate, a year and a half, two years as lieutenant governor. I was a prosecutor for many years. I ran for president of the United States, and now I have been secretary of state for 3½ years. I have met everybody in the world like Boris Johnson. Or not. I don’t know what you mean by ‘like’ Boris Johnson.”

There are indications that Johnson is acting with more decorum since assuming his new post. In his meeting in Brussels with the E.U.’s Foreign Affairs Council, Johnson delivered the message that Britain’s decision to leave the E.U. — as it voted to do last month — did not mean it was abandoning Europe.

French Foreign Minister Jean-Marc Ayrault, who has said Johnson “lied a lot” to rally voters in his push for a British exit, told reporters that he saw a different Johnson this time.

“Boris Johnson, I would say, came to this council with some humility,” Ayrault said.

There are also indications that Johnson’s views are changing. Before being appointed foreign secretary, he wrote in a column in the Telegraph newspaper that cooperation with Syrian President Bashar al-Assad and Russian President Vladimir Putin was needed to fight the Islamic State militant group in Syria.

He took another tack Tuesday before meeting with Kerry and European foreign ministers. “I will be making clear my view that the suffering of the Syrian people will not end while Assad remains in power,” he said in advance remarks released by his office. “The international community, including Russia, must be united.”

Kerry, in turn, quoted Winston Churchill’s assertion that much can be achieved in tough times by Britain and the United States working together.

Kerry said the United States would help Britain and the E.U. make a smooth break.

“In that spirit, I returned to London today to reaffirm our special, unbreakable ties between the United States and Britain,” he said. “It’s clear no shift in administrations, and I’m speaking for the United States, is going to alter the bonds we have.”