Donald Trump will be the next president of the United States after pulling off a stunning upset to defeat the poll-favored Democrat Hillary Clinton. Trump has vowed to make big changes in the country's foreign policy. And world leaders' congratulations to him are mixed with concern. CCTV's Jessica Stone reports. 

After a late night of his own watching election returns, U.S. President Barack Obama delivered a pep talk to a nation -- still digesting one of the biggest political upsets in U.S. history: the election of Donald Trump as America's next commander-in-chief.

"We are now all rooting for his success in uniting and leading this country. The peaceful transition of power is one of the hallmarks of our democracy."

Trump has pledged to roll back global trade deals from Asia to the Americas. He's asked allies to pay more for their defense and called the Iran nuclear deal one of the worst he's ever seen. While Iran on Wednesday called for a Trump administration to stick to the agreement, Trump's vow to revisit it won him support from Israel's prime minister who says the deal endangers Israeli safety. "You are a great friend of Israel, over the years you've expressed your support consistently, and I deeply appreciate it. I look forward to working with you to advance security, prosperity and peace."

But after reaching historic global agreement to curb climate change -- and organizing an international coalition to fight terror group, ISIL -- some global leaders were more reserved in their response to Trump's win - offering congratulations but also concern about the U.S. role as a global leader.

"France must be strong and take its responsibilities all around the world, as I have done since 2012. This context also calls for a united Europe," said Francois Hollande, French president.

U.N. secretary-general Ban Ki-moon said, "People everywhere look to the United States to use its remarkable power to help lift humanity up, and to work for the common good."

The current U.S. president says he tried to make all of the country's global commitments during the past eight years -- as durable and enduring as possible. We may learn just how tight those deals are - as his successor Donald Trump puts them to the test.