Secretary of State John F. Kerry, a Francophile to the bone, loves Paris.

Never was his affinity for the City of Light more poignant than it was Thursday night, as he landed in Paris and spoke in highly personal terms about why he extended an overseas trip to pay his respects at two sites where 16 people died in terrorist attacks last week.

Kerry was not just representing the United States, which has come under fire for not sending a high-profile official to a unity march Sunday in this grief-
stricken city.

“My visit to France is basically to share a big hug with Paris and to express the affection of the American people for France and for our friends there who have been through a terrible time,” he said in Bulgaria, the previous stop on his trip.

Kerry said he expected to make an appearance Friday at the Paris city hall accompanied by singer James Taylor, who plans to serenade the city with one of his most famous songs, “You’ve Got a Friend.”

The emotional note was sounded at the end of a trip that had a serious purpose, as Kerry encouraged Bulgaria, the European Union’s poorest country, to fight corruption and develop new energy sources­ to minimize outside influence.

Kerry’s visit to that NATO member nation, once considered the most loyal of Soviet satellites, was aimed at bolstering its wobbly economy and countering Russian influence.

He met with Bulgaria’s president, prime minister and foreign minister, and he said they spent a significant amount of time talking about ways to diversify the country’s energy supply. Bulgaria depends on Russia for 85 percent of its natural gas supply and all of its nuclear energy.

“No country in the world should be totally supplied with its energy from one other country,” Kerry said in a news conference with Prime Minister Boyko Borisov.

Bulgaria had high hopes for new investment and jobs related to a proposed South Stream gas pipeline that would run across its territory, bypassing Ukraine to deliver Russian gas to southern Europe. But Moscow abruptly called off the project last month, opting for a new hub along the Turkish-Greek border.

Kerry said the United States wants to help the government in Sofia find “practical steps to enhance energy security in Bulgaria and across Europe.”

Several ideas are under consideration, according to the State Department. One is to build a gas spur from Greece, although that could be years away. Another would be to build a nuclear power plant, although a contract with Westinghouse Electric for such a facility has stalled.

Kerry said the Obama administration would send an envoy to Bulgaria and explore ways to help finance the projects.

Although Kerry said the efforts were not aimed at Russia, he also reaffirmed to Bulgaria the U.S. commitment to defend a fellow NATO member if it is invaded. He said the United States would conduct more military exer­cises with Bulgaria. And he noted that there was evidence of “some Russian engagement, through financial support, in the politics of Bulgaria.”

Kerry also exhorted the government to fight corruption, saying the United States is committed to securing a “strong and sovereign” Bulgaria.

A senior State Department official told reporters traveling with Kerry that Bulgaria is an ally in need of assistance because it is hampered by graft, energy dependence on Russia and an anemic economy. Corruption has given Moscow a pathway to exercise undue influence over the nation, the official said.

“If and as they deepen and broaden their commitment to rule of law, we also believe we can do more together on the economic side,” the official said, adding that corruption is not just a threat to democratic institutions. “It is also a wormhole for foreign influence. It’s really essential that Bulgaria tackle it more energetically.”