President Donald Trump addresses the United Nations Security Council during the 73rd session of the United Nations General Assembly, at U.N. headquarters in New York, Sept. 26, 2018. Left is United Nations Secretary-General Antonio Guterres.
President Donald Trump addresses the United Nations Security Council during the 73rd session of the United Nations General Assembly, at U.N. headquarters in New York, Sept. 26, 2018. Left is United Nations Secretary-General Antonio Guterres.

WHITE HOUSE - President Donald Trump is accusing China of meddling in upcoming U.S. elections.

"Regrettably, we found that China has been attempting to interfere in our upcoming 2018 election coming up in November against my administration," Trump said during an address Wednesday morning as he chaired his first U.N. Security Council meeting.

"They do not want me, or us, to win because I am the first president ever to challenge China on trade. And we are winning on trade. We are winning at every level."

Shortly after Trump's remarks, China's foreign minister rejected his accusations of election meddling.

Foreign Minister Wang Yi told reporters that Beijing follows the principle of non-interference in other countries' affairs and refuses to accept "unwarranted accusations" against China.

Later Wednesday, Trump said in a tweet: "China is actually placing propaganda ads in the Des Moines Register and other papers, made to look like news."

China's state media has been placing paid supplements in major American newspapers for at least several years. Although some journalists in the U.S. have criticized the practice as unethical, it has become common for countries and companies to strike deals for this kind of paid content that does not go through a newspaper's editorial channels.

Trump's accusation of Chinese election meddling further raises pressure against Beijing during an escalating trade war. Last week, he accused China of trying to sway the upcoming U.S. midterm elections by targeting voters who supported him in 2016.

WATCH: Trump on China

"China has openly stated that they are actively trying to impact and change our election by attacking our farmers, ranchers and industrial workers because of their loyalty to me," Trump wrote on Twitter.

Prices for many key U.S. agricultural products have plummeted since the start of the U.S.-China trade war, as Chinese importers look to other countries for their supply.

During a briefing to White House reporters Wednesday afternoon, a senior administration official said that Beijing has been using "political, economic, commercial, military and informational tools to benefit the interest of the Chinese Communist Party" in ways that go beyond how countries normally engage with each other.

Chinese Foreign Minister Wang Yi listens as Presid
Chinese Foreign Minister Wang Yi listens as President Donald Trump speaks during a United Nations Security Council session, at U.N. headquarters in New York, Sept. 26, 2018.

The official mentioned Chinese censorship, propaganda, cyberbullying, and China's visa selection process as examples of how China is actively interfering in the American political system. The official said these practices have reached "an unacceptable level."

The official added that Chinese state-run media agencies operating in the U.S. need to be registered under the Foreign Agents Registration Act, a law that would treat them as lobbyists working for a foreign entity.

Vice President Mike Pence is expected to expand on the administration's complaints over Chinese influence efforts in an address next week in Washington.

China or Russia?

While Russia's role in manipulating the 2016 election in Trump's favor is the subject of the special counsel's investigation, until recently there were no allegations of Chinese political meddling. Beijing has been accused of corporate espionage for years and in 2015 allegedly hacked a database containing personal information on as many as four million people who applied for jobs with the U.S. government.

Secretary of State Mike Pompeo was also asked about Russia's threat to upcoming U.S. elections, and he responded by mentioning several countries.

"The U.S. government is actively engaged in efforts to ensure that the Russians, the Chinese, the Iranians, the North Koreans, all of those with malintent for America will not have the capacity to have substantial interference in the American elections," he said in an interview with CBS news Wednesday.

FILE - Director of National Intelligence Dan Coats
FILE - Director of National Intelligence Dan Coats testifies during a Senate Intelligence Committee hearing on Capitol Hill in Washington, Feb. 13, 2018.

On Tuesday, Director of National Intelligence Dan Coats warned that China's growing prowess in cyberspace is a bigger, more dangerous threat to the United States than Russia's attempt to undermine U.S. elections.

Speaking at a cybersecurity conference Tuesday at The Citadel, a military college in Charleston, South Carolina, Coats characterized the Chinese threat as deliberate, methodical and subtle, and warned that Beijing is on a path that could lead to global supremacy.

U.S.-China tariffs war

On Monday, a new round of U.S.-imposed duties on $200 billion worth of Chinese goods and a retaliatory set of tariffs imposed by Beijing on $60 billion worth of U.S. goods took effect.

The U.S. has already imposed tariffs on $50 billion worth of Chinese goods, and China has retaliated on an equal amount on U.S. goods.

Earlier this month, Trump threatened more tariffs on Chinese goods — another $267 billion worth of duties that, together with the existing tariffs, would cover virtually all the goods China exports to the United States.

Jeff Seldin contributed to this report.