WASHINGTON -- Soon after President Donald Trump was sworn in, his administration announced the U.S. withdrawal from the Trans-Pacific Partnership, a trade pact championed by former President Barack Obama and Japanese Prime Minister Shinzo Abe.

The White House on Friday also wasted no time in declaring a renegotiation of the North American Free Trade Agreement, or NAFTA. Trump is expected to take a more isolationist, protectionist stance, and the international community is concerned that the U.S. will continue to draw inward.

Trump was sworn in as the 45th president of the U.S. on Friday, repeating his campaign pledges of putting American interests first and restoring national glory to a deeply polarized public.

"We are transferring power from Washington, D.C., and giving it back to you, the people," Trump, dressed in a navy suit and red tie, said in his inaugural address. He pledged to rebuild the U.S. and create jobs under his "America first" policy, and urged the country to unite.

Trump's term lasts until January 2021. At 70, he is the oldest president in U.S. history and the first to have no experience in government or the military. He is expected to roll back Obama's liberal policies, focusing more on making deals than on global order and principles. His policies could lead to confusion both at home and abroad.

Earlier that morning, Trump prayed at a church near the White House with his wife Melania. The couple then met former President Barack Obama and his wife Michelle before arriving at the Capitol, where the inauguration was held.

After Vice President Mike Pence was sworn in, Trump took his oath with his hand on two Bibles -- one used by former President Abraham Lincoln in the 19th century, and another his mother gave him as a child.

Sean Spicer, Trump's White House press secretary, told reporters Thursday that the inaugural speech will touch on such topics as infrastructure, education and manufacturing. It will be "less of an agenda and more of a philosophical document," he said.

Trump had the lowest approval rating of any incoming president at around 40%, and at least 60 Democratic legislators boycotted his inauguration. Though the Republican Party took back the White House for the first time in eight years and holds a majority in both houses of Congress, the administration's future path depends on how much public support it receives.

The Senate is set to confirm the first of Trump's picks, James Mattis as defense secretary and John Kelly as secretary of homeland security, on Friday, according to U.S. news outlets. In contrast, former President George W. Bush in 2001 and Obama in 2009 both had seven of their cabinet picks confirmed on the day of their inauguration.

A key question on Trump's foreign policy is how he plans to deal with Russia and China. Washington imposed sanctions on Moscow after it annexed Crimea, and Beijing is pushing back against Trump's suggestion of revisiting the "One China" policy, which holds that Taiwan and China are one country. In terms of the economy, many are focused on his promises to cut taxes and increase government spending.

Though initially considered a fringe candidate, Trump secured the Republican nomination by highlighting his business experience. He then won the presidential race against Democratic rival Hillary Clinton, despite most polls predicting the opposite result. He railed against the political establishment and found support among white, low-income Americans who felt left behind by the country's economic recovery. He saw an opportunity in the economic rifts that divide American society.