Editorial use onlyMandatory Credit: Photo by Jacques Witt/SIPA/REX/Shutterstock (10010310au)President of Mexico Enrique Pena Nieto, President of Turkey Recep Tayyip Erdogan, President of South Africa Matamela Cyril Ramaphosa, British Prime Minister Theresa May, President of France Emmanuel Macron, U.S. President Donald Trump, Prime Minister of Japan Shinzo Abe, President of Argentina Mauricio Macri, President of the People's Republic of China Xi Jinping, Singapore Prime Minister Lee Hsien Loong, Russian President Vladimir Putin, Prime Minister of Australia Scott Morrison, President of Brazil Michel Temer and Prime Minister of Italy Giuseppe ConteG20 Summit, Buenos Aires, Argentina - 30 Nov 2018

With the G20 in full swing, the powers that be gathered Friday night at the leaders’ dinner at Teatro Colón in Buenos Aires. First Lady Melania Trump dressed for the occasion in a custom Reem Acra column dress with a vintage belt and metallic pumps. Her yellow diamond stud earrings were chosen to accent the glittery belt. FLOTUS originally selected the dress for another occasion, but it turned out to be better suited for this one, her stylist Hervé Pierre said.

She and Acra, who is based in New York, are “very good friends,” and the designer suited up Trump for a formal dinner the night before last year’s inaugural, the stylist said. Describing Acra as “a dream,” Pierre said, “Designers can be difficult. [laughing] She is really nice.”

Of course, speculation centered on diplomatic relations, especially Saudi Crown Prince Mohammed bin Salman’s welcome to Russian President Vladimir Putin, as well as the overheard informal exchange between the prince and French President Emmanuel Macron. While Trump met with prime minister of India Narendra Modi and Japan’s prime minister Shinzō Abe earlier in the day, the dinner lends itself to more relaxed conversations among world leaders. German Chancellor Angela Merkel had some ground to cover, having arrived at the summit behind schedule after having her flight diverted due to mechanical problems. After an emergency landing in Germany, Merkel had to fly Iberia Airways from Madrid Friday to get to Buenos Aires.

Back to less weighty matters, Ivanka Trump also made a cameo at the dinner, turning up in an ivory-colored off-the-shoulder pantsuit. The First Lady opted for a floral Gucci dress with a green border from Alessandro Michele for an outing with her Argentinean counterpart, Juliana Awada, at Buenos Aires’ Villa Ocampo on Friday afternoon. The sleeveless style was selected with Argentina’s summery temperatures in mind, according to Pierre.

For Thursday’s departure for Buenos Aires, the First Lady showed some solidarity for him by wearing a brown sweater by Atelier Caito for Hervé Pierre with a Ralph Lauren chocolate brown leather coat and a purple Derek Lam skirt. And upon arrival at Ministro Pistarini International Airport, she had switched skirts to wear an ivory leather skirt from Pierre’s collection with pony-print Manolo Blahnik pumps and the aforementioned items.

Trump has kept a brisk place this week, unveiling the 18-foot White House Christmas tree and subsequently kicking off a great debate on social media about the conical all-red trees. So much so that two days later she addressed the issue after speaking at Liberty University. Trump said of the holiday decor, “We are in the 21st century and everybody has a different taste, I think they look fantastic.…In real life, they look even more beautiful,” according to a pool press report. (“American Treasures” is this year’s theme.) Tuesday she helped compile care packages with the American Red Cross for American service members stationed overseas. And for one of the many holiday parties at the White House, she wore a sleeveless white Dior dress she first donned for a trip to Hawaii last year.