Secretary of State John Kerry was in Cuba on Friday for the official re-opening of the U.S. embassy in Havana, a move that began a new chapter in relations between the two countries.

In a ceremony attended by about 300 U.S. and Cuban officials, surrounded by hundreds of onlookers, Kerry made remarks and presided over the raising of the flag over the embassy. The Post’s Karen DeYoung writes about the historic moment:

Kerry is the highest-ranking U.S. official to visit Cuba since the Franklin Roosevelt administration. “As two people who are no longer enemies or rivals, but neighbors,” he said in English and Spanish, it is “time to unfurl our flags, raise them up, and let the world know that we wish each other well.”

Neither country, he said, has “illusions about how difficult our new relationship will be.” But “we are each confident in our intentions, in the contacts we have made, and the friendships we have begun to forge,” Kerry added in an address that quoted the 19th century Cuban nationalist hero José Martí.

Watch the flag being raised here:

The ceremony echoed the past in several respects (check out a timeline of U.S.-Cuba history starting in 1959 here). The three Marine veterans who lowered the flag over the embassy in 1961 took part, handing a new banner to a new contingent of Marine guards. All three are now in the 70s, according to the Post’s Dan Lamothe.

Watch a video released by the State Department of the Marine veterans reflecting on what happened in 1961:

Kerry will meet with leaders of Cuban civil society later in the day in a nod to differing opinions about the decision to restore U.S.-Cuba ties:

While many support the opening, others have joined some U.S. lawmakers in charging that the administration gave up the principal U.S. leverage in Cuba and got little in return from the repressive government.

Kerry has rejected criticism that Cuban dissidents were not invited to attend the morning embassy ceremony, describing it as a “government to government event.” Several senior administration officials, discussing the sensitive issue on condition of anonymity, said they were taken aback by the criticism.

Though one Republican lawmaker accompanied Kerry as part of the delegation, most in the GOP have criticized the Obama administration for its policy on Cuba. Several Republican presidential candidates took the opportunity to weigh in on Friday:

Cuban American Sen. Marco Rubio (R-Fla.) delivered a foreign policy speech in which he pitched plans to roll back the Iran nuclear deal and the restoration of ties between the Untied States and Cuba, the Post’s Karoun Demirjian reports:

With Iran, Rubio said he’d replace the deal with “crippling sanctions,” “crushing new measures” and stepped up military forces in the Middle East; while in Cuba, he’d demand the Castro regime institute quid pro quo political reforms for maintaining diplomatic ties and would slap a “state sponsor of terror” designation on the country, again.

Rubio’s speech for the Foreign Policy Initiative in New York comes as the Obama administration is urging members of Congress to pledge their support for the Iran agreement, which lawmakers will vote on next month, and as Secretary of State John F. Kerry arrives in Havana to participate in a flag-raising ceremony. Rubio, who is Cuban American and represents a state with a large Cuban population, took a direct dig at that celebration Friday as well, pointing out that the United States had not invited Cuban dissidents, and promising that if elected president, Cuban dissidents and others like them would be invited to his inauguration.