Cubans dance with tourists at Mi Conuco Cafeteria in Havana in January. A giant poster of Fidel Castro hangs on the wall. Will U.S. diplomats come here? (Sarah L. Voisin/The Washington Post)

When Secretary of State John F. Kerry arrives here Friday for a ceremony to raise the Stars and Stripes once more at the U.S. Embassy in Cuba, he’ll be the highest-ranking American official to set foot on the island in 70 years.

His demeanor could matter as much as his remarks. Will he maintain the all-business approach that U.S. diplomats typically project here? Or will he treat the occasion as a celebration, signaling perhaps that it’s okay to have fun in Cuba again?

It’s not an abstract question. The Obama administration’s decision to restore diplomatic relations with Cuba is banked on the belief that the United States can do more to encourage change on the island through a soft-power strategy of “engagement.” And a big part of that, in Cuba, means figuring out how to change the profile of U.S. diplomacy — and throw a good party again.

Kerry will not have a lot of time for non-ceremonial festivities. He will not spend the night in Havana, and his day will be well scripted. The official delegation — to include representatives from the Commerce, Defense and Treasury departments and eight members of Congress — will total no more than 20. But a second official plane will bring a group of selected Cuban Americans, business representatives, and the three long-retired Marines who lowered the U.S. flag the last time it flew here, in January 1961.

Havana’s festive atmosphere has long befuddled visiting American politicians fearful they could be accused of disporting themselves inappropriately in a repressive environment. Now it’s up to American officials to drop their guard a bit in the hopes that Cuba will do the same, and that engagement will win new U.S. influence.

During the 38 years that the U.S. mission here operated as a downgraded “interests section,” American officials hosted many of the types of events that they do elsewhere: Fourth of July receptions, dinners for visiting VIPs and special-invitation parties to watch the Super Bowl or presidential debates. The palatial 35,000-square-foot official U.S. ambassadorial residence in Havana’s former “Country Club” district has a reputation for good brownies — but parties that rarely last beyond 9 p.m.

With a few exceptions, though, Cuban officials were never allowed by their own government to attend.

Cuba’s boycott only hardened as the United States began inviting government opponents to the receptions. It was only at times of improving ties — like the current thaw — that a few Cuban artists, musicians and others started showing up again, mingling with American officials and dissident activists over mojitos and light jazz. But the presence of dissidents still kept government officials away, and that put a crimp on the practice of informal diplomatic engagement.

Friday’s flag-raising put U.S. diplomats in the same knot. They have resolved it by labeling the embassy ceremony a “government-to-government” event that a senior State Department official said would signify “this new ­relationship and the reopening of an embassy.” The official, who briefed reporters Wednesday under ground rules of anonymity, said the guest list was not given to the Cuban government, but declined to provide a number of attendees, saying the department was still awaiting responses to some invitations.

Immediately after the morning ceremony, Kerry will meet with Cuban Foreign Minister Bruno Rodríguez at the ministry. The two will then hold a joint news conference, as they did in Washington when Rodríguez raised his own country’s flag at the Cuban Embassy on July 20, when diplomatic relations were formally reestablished. While the U.S. Embassy has been open for business since then, the official flag-raising has awaited Kerry’s arrival.

There are no plans for a Kerry meeting with either Cuban President Raúl Castro or his brother, former Cuban leader Fidel Castro, the official said.

Representatives of Cuban “civil society,” including dissidents, entrepreneurs and other diplomats, are to be hosted by Kerry at an afternoon reception held at the residence, currently occupied by U.S. Charge d’Affaires Jeffrey DeLaurentis.

Kerry, in an interview late Wednesday with the Spanish-
language TV network Telemundo, said that the dissidents were “not invited . . . quite openly” to the embassy event “because that is a government-to-government moment, with very limited space, by the way, which is why we are having the reception later in the day, in which we can have a cross section of civil society, including some dissidents.”

Further, he said, “I will take an open, free walk in Old Havana at some point of the day. I look forward to meeting whoever I meet and listening to them.”

U.S. officials say they will continue advocating for “universal values” in Cuba. The State Department official said the Obama administration is satisfied with arrangements that have broadened access to the embassy for Cuban citizens. U.S. diplomats, the official said, are now free to travel anywhere in Cuba, provided they notify the government in advance, under reciprocal terms negotiated by the two governments.

In talks with Rodríguez on Friday, the official said, Kerry hopes to accelerate talks over issues including law enforcement and human rights.

But some anti-government activists say they’re being marginalized by the Obama administration’s new Cuba policy, and have started to make the U.S. president an additional target for their protests.

Over the weekend, the government arrested nearly 100 dissidents, including about 50 members of the Ladies in White group who attempted to march wearing Obama masks. The group’s leaders oppose the renewal of diplomatic relations, saying it has encouraged the Castro government to be more repressive.

European diplomats in Cuba have been trying the engagement approach for decades, of course, with mixed success.

One of Havana’s most popular figures is Norwegian Ambassador John Petter Opdahl, a patron of the arts who often opens the doors of his home for parties. The festive times have helped Oslo’s more serious endeavors here for issues such as environmental protection and conflict resolution.

“One of the major reasons for success in our engagement with Cuba and Cubans is that the main theme has always been culture and not politics, and not regime change as such, which frankly is not our business to stimulate or to instigate as diplomats,” Opdahl said.

Building relationships with ordinary Cubans, and especially Cuban musicians, writers and artists, is a key part of it.

“Many of them have opinions, views, dreams — like the rest of us — about the future of Cuba, and very often they have their own way of communicating this to a much wider audience inside Cuba than, for instance, most of the traditional dissidents,” Opdahl said.

But breaking through to Cuban officials is even more difficult, especially for countries that Cuba views warily, according to Paul Webster Hare, who was British ambassador in Havana from 2001 to 2004 and now teaches at Boston University’s Frederick S. Pardee School of Global Studies.

“Cuban officials, unlike in most other foreign postings, do not socialize with foreigners outside office time,” Hare said. “They never invite you to their homes and are warned not to befriend diplomats, particularly from West­ern countries. So they will laugh, dance and joke, but there is always something of a veil.”

DeYoung reported from Washington.