SEOUL, South Korea — As the United States and South Korea prepare for next week’s joint naval exercise, North Korean officials on Friday renewed their threat to launch ballistic missiles near Guam, an American territory in the western Pacific.

The drill, which involves the aircraft carrier Ronald Reagan, is scheduled to begin on Monday in waters east and west of South Korea. The 10-day exercise will check the allies’ “communications, interoperability and partnership,” the United States Navy’s 7th Fleet said in a statement.

The nuclear-powered submarine Michigan arrived at the South Korean port of Busan on Friday. American and South Korean warplanes will also join the exercise, which takes place during heightened tensions over North Korea’s advancing nuclear missile program.

In recent months, President Trump and the North Korean leader, Kim Jong-un, have amplified their countries’ military standoff by exchanging bellicose statements and personal insults.