Republican President Donald Trump on Monday vowed to win the November election and rebuild the U.S. economy shattered by the coronavirus pandemic, after he was formally nominated by his Republican Party for a second term in the White House.

"This is the most important election in the history of our country...our country can go in a horrible, horrible direction or in an even greater direction," Trump, 74, said as he made a surprise visit to the venue of the Republican National Convention, which started Monday in the southern state of North Carolina.

President Donald Trump announces that the Food and Drug Administration is issuing an emergency authorization for blood plasma as a coronavirus treatment during a press conference in James S. Brady Briefing Room at the White House on on August 23, 2020 in Washington, DC.(Getty/Kyodo)

Trump plans to deliver his official nomination acceptance speech on Thursday from the White House, as the four-day convention was scaled down due to the pandemic that has left more than 176,000 people dead in the country.

By showing up at the event, Trump apparently sought to present himself as a strong leader in contrast with his 77-year-old Democratic rival Joe Biden, who has conducted most of his campaigning online from his home and accepted his nomination as Democratic presidential candidate last week without traveling to the party's convention site in Wisconsin.

Trump is currently trailing the former vice president in most of the top six battleground states crucial for re-election, such as the Midwestern state of Michigan and the southern state of Florida, according to averages of the latest surveys compiled by major poll tracking website Real Clear Politics.

In his nearly one-hour speech at the convention, Trump shrugged off the Democrats' criticism that he is an incompetent leader who mishandled the public health crisis. He boasted achievements during his first term in office and highlighted signs of an economic recovery following the pandemic-induced shutdown.

"Before the plague came in from China....we were going in a direction like we have never seen -- the most successful economy in the history of our country," Trump said, adding that he has also "fixed a lot of our broken and bad trade deals" and "stood up to China like nobody's ever" done.

"Next year is going to be an incredible, it's going to be a great, great year," Trump said, pledging that in his second term, his administration will create 10 million new jobs in 10 months and offer tax credits for companies that repatriate operations from China.

He also said he will continue to impose tariffs on countries "that take advantage of the United States."

In the 2016 election, Trump, a New York real estate mogul who had never held public office before, ran his campaign as a political outsider seeking to upend the establishment. He appealed to white working-class voters by speaking to their resentment against globalization and free trade deals, which he viewed as job-killers.

Trump still portrays himself as an outsider, drawing attention to his Democratic rival's tenure of nearly half a century in Washington as a senator and two-term vice president under Barack Obama.

The Democratic Party has pitched Biden as an experienced leader who can move the country out of the health and economic crisis, while criticizing Trump's "America First" policy for causing the United States to retreat from the global stage, allowing adversaries to fill the void and weakening U.S. alliances.

Trump has pulled the United States from international agreements that he believes do not serve U.S. interests, such as the Trans-Pacific Partnership regional free trade deal, the Paris climate accord and a multinational deal to curb Iran's nuclear program.

He has also stirred controversy through his transactional approach to longstanding U.S. alliance relationships, pressuring countries including Japan and South Korea to fork over significantly more money in exchange for U.S. security protection.

On China, Trump spent nearly two years in a tit-for-tat tariff war as his administration pushed to reduce the chronic U.S. trade deficit with the Asian country and to address alleged intellectual property and technology theft by Chinese companies.

The United States signed a partial trade deal with China in January, but what appeared to be a sign of thawing ties quickly dissipated as the coronavirus pandemic, which was initially detected in China late last year, spread to the United States with devastating impacts on the U.S. economy.

The Trump administration has since shifted to an increasingly hawkish stance against Beijing, with their confrontation deepening over areas ranging from the economy to military, technology and ideology.

"We're fighting off this horrible thing that was delivered by China, and it was by China...I'll let them know we're never going to forget what they did," Trump said Monday.

Political pundits say that China-bashing is received well among U.S. voters amid souring sentiment against the world's second-largest economy.