G-20 Summit

President Donald Trump talks with reporters before traveling to the G20 Summit in Buenos Aires, on the South Lawn of the White House, Thursday, Nov. 29, 2018, in Washington. (AP Photo/Evan Vucci)

Ukrainian soldiers stand atop an APC near Urzuf, south coast of Azov sea, eastern Ukraine, Thursday, Nov. 29, 2018. Ukraine put its military forces on high combat alert and announced martial law this week after Russian border guards fired on and seized three Ukrainian ships in the Black Sea. (AP Photo/Evgeniy Maloletka)

In this Nov. 17, 2018, photo, resident Donald Trump boards Air Force One for a trip to visit areas impacted by the California wildfires at Andrews Air Force Base, Md. Marathon days. Red-eye flights. Jam-packed agendas. As Trump departs Thursday, Nov. 29 to attend the G20 summit, he will be making the most of a scaled-back international schedule.(AP Photo/Evan Vucci, File)

Ukrainian President Petro Poroshenko, second from right, speak with soldiers during a military training at a military base in Chernihiv region, Ukraine, Wednesday, Nov, 28, 2018. Russia and Ukraine traded blame after Russian border guards on Sunday opened fire on three Ukrainian navy vessels and eventually seized them and their crews. The incident put the two countries on war footing and raised international concern. (Mykola Lazarenko, Presidential Press Service via AP)

Russian President Vladimir Putin speaks during a meeting in Moscow's Kremlin, Russia, Tuesday, Nov. 27, 2018. Putin and German Chancellor Angela Merkel spoke on the phone in the early hours on Tuesday, and the Russian president expressed a "serious concern" about what the martial law in Ukraine might entail. The Kremlin warned Tuesday that Ukraine’s declaration of martial law over Russia’s seizure of three Ukrainian ships might trigger a flare-up in hostilities in eastern Ukraine, while Kiev blamed Russia for parading captured Ukrainian seamen on television. (Alexei Nikolsky, Sputnik, Kremlin Pool Photo via AP)

Chinese President Xi Jinping, left, and Spain's King Felipe walk side by side during a welcome ceremony at the Royal Palace in Madrid, Spain, Wednesday, Nov. 28, 2018. Chinese president Xi Jinping has arrived Tuesday in Spain for the first leg of an international tour that will cover a global summit in Argentina and visits to Panama and Portugal. (AP Photo/Manu Fernandez)

People walk past a bank electronic board showing the Hong Kong share index at Hong Kong Stock Exchange Wednesday, Nov 28, 2018. Asian shares were mixed Wednesday after a wobbly day of trading on Wall Street, and uncertainty loomed as investors looked toward the G-20 meeting of world leaders later in the week.(AP Photo/Vincent Yu)

Tunisian President Beji Caid Essebsi, right, shakes hands with Saudi Crown Prince Mohammed bin Salman upon his arrival at the presidential palace in Carthage near Tunis, Tunisia, Tuesday, Nov. 27, 2018. Traveling abroad for the first time since the killing of Saudi journalist Jamal Khashoggi, the crown prince is visiting allies in the Middle East before heading to a G20 summit in Argentina later this week. (AP Photo/Hassene Dridi)

A man rides a bicycle past a banner promoting the G20 summit at the Costa Salguero Center, in Buenos Aires, Argentina, Tuesday, Nov. 27, 2018. Thousands of police and security agents will guard the Group of 20 industrialized nations' world leaders during the two-day meeting that starts Friday. (AP Photo/Natacha Pisarenko)

Ground staff collect the corner flags after the final Copa Libertadores soccer match against Argentina's Boca Juniors was suspended, at Antonio Vespucio Liberti stadium in Buenos Aires, Argentina, Sunday, Nov. 25, 2018. South American soccer body CONMEBOL said on Sunday that the second leg of the final will be rescheduled after Boca’s bus was attacked by River fans on Saturday. (AP Photo/Ricardo Mazalan)