Trump will explain tariffs on electronics on Monday

Key global stock markets tumbled upon opening on Monday as the world's reaction to President Donald Trump's tariffs campaign continued -- and as U.S. futures signaled more turmoil for American markets.

In the U.S., futures for the S&P 500 lost 4.5%, those for the Dow Jones Industrial Average shed 4% and Nasdaq futures lost 4.8% as of Monday morning.

In Japan, the Nikkei 225 index lost nearly 9% shortly after the market opened. Hong Kong's Hang Seng Index dropped more than 13%.

The pan-European Stoxx 600 index dropped more than 6%, Germany's DAX index fell 10%, France's CAC lost 6.6% and Italy's FTSE MIB slid 5.7%. The British FTSE 100 index fell 6% upon opening.

President Donald Trump said America's trade deficit with China must first be resolved before he considers making a deal regarding his sweeping tariffs against the country.

"We have a trillion-dollar trade deficit with China -- hundreds of billions of dollars a year we lose with China. And unless we solve that problem, I'm not going to make a deal," the president told reporters on Air Force One on Sunday.

"Now, I'm willing to deal with China, but they have to solve their surplus. We have a tremendous deficit problem with China. They have a surplus of at least a trillion dollars a year. I think it's like a trillion one, and I want that solved," Trump said.

The president also discussed with reporters the TikTok deal being in limbo, saying that China did not approve the deal because of the tariffs on the country.

"The report is that we had a deal -- pretty much for TikTok, not a deal, but pretty close and then China changed the deal because of tariffs. If I gave a little cut in tariffs, it approved that deal in 15 minutes, which shows you the power of tariffs," Trump said.

-ABC News' Hannah Demissie

While speaking with reporters on Air Force One on Sunday, President Donald Trump said he didn't crash the stock market on purpose and that he doesn't know what will happen to the market, but believes the country will come out stronger.

"Now what's going to happen with the market? I can't tell you, but I can tell you, our country has gotten a lot stronger, and eventually it'll be a country like no other, it'll be the most dominant country economically in the world," Trump said.

Asked if there's a pain in the market he's unwilling to tolerate, Trump said he doesn't want anything to go down.

"I don't want anything to go down, but sometimes you have to take medicine to fix something and we have such a horrible -- we have been treated so badly by other countries because we had stupid leadership that allowed this to happen," the president added.

-ABC News' Hannah Demissie

Despite Trump’s reposting of a video that claimed he’s purposely crashing the stock market, the president’s top economic adviser on Sunday denied that’s his strategy.

On ABC News’ “This Week,” anchor George Stephanopoulos pointed out the post on Trump’s Truth Social platform to White House National Economic Council Director Kevin Hassett and asked if he was trying to drive markets down to force the Fed to lower interest rates.

On Friday, Federal Reserve Chair Jerome Powell said at a conference that Trump's tariff policy will hike prices and slow economic growth. Minutes before Powell spoke, Trump posted on Truth Social, "This would be a PERFECT time for Fed Chairman Jerome Powell to cut Interest Rates,” and claimed without evidence that political considerations have played a role in Powell's decision-making on interest-rate policy.

Pressed by Stephanopoulos on the post, Hassett said the White House respected the Fed’s independence and denied that Trump was trying to pressure it to lower rates.

“It is not a strategy for the markets to crash. It's a strategy to create a golden age in America for the American worker. That's his strategy,” Hassett said.