The first day of the G20 summit in Buenos Aires wrapped up Friday evening, the air heavy with lingering uncertainties over whether the attending leaders from industrialized nations would be able to agree upon a final statement before the end of the summit. 

At the summit's opening, Argentine President Mauricio Macri made a plea for world leaders to have a "sense of urgency" and take actions "based on shared interests."

But over the course of the day, divisions over the Paris climate accord and the World Trade Organization were palpable, with the United States singled out for impeding progress on finding common global solutions.  

An official in the French president's office said a final statement may include language that sets the US apart from the 19 other attending nations, while a US official said that the White House was "optimistic" about the document.

Argentine officials also voiced progress, saying that trade talks had moved forward over the course of the day. 

The trade war between the United States and China, Russian aggression in Ukraine, and the suspected involvement of Saudi Crown Prince Mohammad bin Salman in the slaying of dissident journalist Jamal Khashoggi have been contentious issues so far.

High-stakes bilateral meetings began on Friday and will continue over Saturday, with US President Donald Trump's meeting with Chinese President Xi Jinping, as well as with German Chancellor Angela Merkel, to be in particular focus.

Merkel will meet Saturday with Vladimir Putin, while Trump canceled a planned one-on-one with the Russian president.

The chancellor had to reschedule her meetings for Saturday after technical problems with the government plane caused her delayed arrival.

Read more: On the threshold of the global contradictions: G20 - Interview by Evgeniy Mikhailov

What happened on day 1:

• Trump, who was aiming to close a number of deals at the summit, inked a new trade pact with Mexico and Canada to replace NAFTA.
• Trump said there were "good signs" for a potential trade deal with Beijing ahead of a Saturday dinner meeting with his Chinese counterpart Xi.
• China, the UN and France united Friday and pledged support for the Paris climate accord in an attempt to boost support for the treaty and the upcoming climate summit.
• Theresa May, the first British prime minister to visit the Argentine capital, told British media she wanted to "be robust" in discussions with Salman over the war in Yemen and Khashoggi's death.
• EU Council President Donald Tusk said that the EU would likely extend sanctions on Russia over its "totally unacceptable" seizure of Ukrainian ships and their crews near Crimea.
• Putin criticized sanctions on Russia and called for securing a nuclear deal with Iran, despite the US withdrawal from the pact, to "prevent a new round of tensions over the Iranian nuclear program." He also warned that Washington's planned exit from the 1987 Intermediate-Range Nuclear Forces Treaty "creates risks of an uncontrollable arms race."
• Thousands of protesters marched through parts of Buenos Aires, while 22,000 police stood at the ready in case of violence or destruction.
• The leaders enjoyed a musical performance at the historic Teatro Colon after the day's business procedures wrapped up.