Elon Musk, the chief executive of Tesla, and Giorgia Meloni, the prime minister of Italy, were the stars of a black-tie dinner in New York on Monday that highlighted Mr. Musk’s increasing involvement in politics.

Ms. Meloni had chosen Mr. Musk to introduce her as she received a Global Citizen Award from the Atlantic Council, a Washington think tank that cited “her political and economic leadership of Italy, in the European Union” and of the Group of 7 nations “as well as her support of Ukraine in Russia’s war against it.”

The prime minister and the billionaire business leader have bonded over the years. They share concerns about artificial intelligence and declining birthrates in Western countries, which Mr. Musk has called an existential threat to civilization.

He described Ms. Meloni on Monday as “someone who is even more beautiful inside than outside” and “authentic, honest and thoughtful.”

“That can’t always be said about politicians,” Mr. Musk added, to laughter from the crowd of 700 at the Ziegfeld Ballroom in Manhattan.

After thanking Mr. Musk for his “precious genius,” Ms. Meloni delivered a passionate defense of Western values. While rejecting authoritarian nationalism, she said, “we should not be afraid to defend words like ‘nation’ and ‘patriotism.’”

She stressed that her vision was “democratic and secular.”

Mr. Musk, sitting next to his mother, Maye Musk, nodded as Ms. Meloni spoke, and he stood and applauded energetically when she finished. Afterward their table was mobbed by people trying to take selfies with them or get a word with Mr. Musk.

Also receiving awards were Nana Akufo-Addo, the president of Ghana; Kyriakos Mitsotakis, the prime minister of Greece; and Miky Lee, vice chair of CJ Group, who is responsible for the South Korean conglomerate’s entertainment and media holdings.

Since becoming prime minister of Italy in 2022, Ms. Meloni has dispelled fears that her party, which has far-right roots, would lead Italy back to fascism. She has established good relationships with mainstream European leaders and the Biden administration, and aligned with them on key international issues such as support for Ukraine in its war against Russia.

Ms. Meloni is seen as more acceptable to other European leaders than Viktor Orban, the authoritarian prime minister of Hungary, and rather as a bridge between the far right and Europe’s mainstream parties.

Mr. Musk has moved increasingly to the right, endorsing conspiracy theories on X, the social media platform he owns, and backing former President Donald J. Trump in the November election. He has formed friendships with right-wing political leaders like Argentina’s Javier Milei and Brazil’s Jair Bolsonaro, often exploiting the relationships to promote his political views and expand his business empire.

Italy’s population is aging and shrinking at the fastest rate in the West, and aside from its right-wing government and rich history, its plummeting birthrate makes it a place of particular interest to Mr. Musk.

“Italy will have no people if these trends continue,” he wrote on Twitter in 2022.

Mr. Musk visited Italy several times last year, including a turn as the star guest when Ms. Meloni’s party held a festival in Rome. He stepped onstage holding one of his children and talked about the importance of having children to “create the new generation.” He said that he worried about Italy’s birthrate and that the country could not rely on immigrants.

“Italy is the people of Italy,” he said, adding, “Please, make more Italians.”

Ms. Meloni has also said Italy is “destined to disappear” unless it changes, and she has long encouraged Italians to have more children.

The two leaders also share an interest in artificial intelligence. “Politics must guarantee that artificial intelligence remains controlled by humans and keeps humans at the center,” Ms. Meloni said earlier on Monday at the United Nations.

They have also stood on the same side of the culture wars, criticizing what Mr. Musk calls “woke mind virus” and Ms. Meloni calls “political correctness.”

Mr. Musk has also shown support for Italy’s anti-immigration policies and for the far-right leader Matteo Salvini, who is on trial in Italy for preventing a boat carrying rescued migrants from docking on Italy’s shore. Mr. Salvini’s party is a coalition partner in Ms. Meloni’s government, and he serves as her deputy prime minister and minister of transportation.

Ms. Meloni told Il Corriere della Sera, Italy’s largest newspaper, that she was an ally of the Republican Party. But while “my political affinities in the American system are evident,” she said in July, “this has not prevented me from working very well with the Biden administration.”

The Atlantic Council describes itself as a nonpartisan forum for political and business leaders to discuss global issues such as economics, security and climate change. The group’s chairman is John F.W. Rogers, an executive vice president at Goldman Sachs who has held several high-ranking U.S. government positions, including under secretary in the State Department.