BEIJING -- South Korea's military said on Friday morning that joint military exercises with the U.S. will go on as planned at the end of August.

North Korea claims the large-scale drills, which will involve about 40,000 combined troops, are rehearsals for war. After the same annually-scheduled exercises last year, Kim Jong Un's regime carried out North Korea's fifth nuclear test.

Earlier, a newspaper on the U.S. island territory of Guam blared the headline: "14 minutes." That's how long it would take for North Korean missiles to reach the island. This week, North Korea's military laid out detailed plans to launch a salvo of four ballistic missiles over Japan and into the sea, landing within about 20 miles of Guam.

The North said Kim would be presented the prospective plans for approval right around the same time the U.S.-South Korean military exercises are scheduled to get underway.

President Trump has, again, asked the president of China, North Korea's most valuable trading partner, to step in and pressure Kim to negotiate.

But China's Foreign Ministry told CBS News on Friday that Beijing has been working hard on the North Korea issue, and paid a big price for its efforts.

CBS News correspondent Ben Tracy says the statement appeared to be a reference to China going along with the recent U.N. sanctions that will limit China's trade with the North.

But President Trump still wants China to do what he simply calls "more."

"I think China can do a lot more, yes, China can," Mr. Trump said. "And I think China will do a lot more."

As Tracy reports, President Trump is simultaneously fueling the escalating confrontation with North Korea, issuing military threats of "fire and fury," while pressuring China to solve the crisis peacefully. He's threatened a trade war with Beijing if China doesn't give the help he wants.

"Look, we have trade with China. We lose hundreds of billions of dollars a year on trade with China. They know how I feel. It's not going to continue like that," Mr. Trump asserted. "But if China helps us, I feel a lot differently toward trade, a lot differently toward trade."

If the U.S. is trying to convince China to take significant action on North Korea, however, Tracy says the Trump administration is using more stick than carrot.

On Thursday the U.S. Navy sailed a destroyer through contested waters in the South China Sea -- just 12 miles off the shore of one of the islands China claims as its own territory.

In a terse statement, China's Foreign Ministry said Friday that the sail-by "severely harmed China's sovereignty and security," and that "China is very displeased."

The Chinese government made another statement Friday morning, urging the U.S. and North Korea to act with caution, and to stop taking turns showing off their military strength.