"We will continue to plan the meeting," State Department spokeswoman Heather Nauert told reporters, adding that Washington had received "no notification" of a position change by North Korea.

"We have not heard anything from that government or the government of South Korea to indicate we would not continue conducting these exercises or would not continue planning for our meeting between President Trump and Kim Jong Un next month."

South Korea's Yonhap news agency reported that Pyongyang had called the June 12 summit into question over the "Max Thunder" joint military exercises between the US and the South.

The US will "have to undertake careful deliberations about the fate of the planned North Korea-US summit in light of this provocative military ruckus," Yonhap quoted the North's official news agency KCNA as saying.

Nauert denied that the exercises were provocative, saying: "Kim Jong Un has said he understands the importance to the United States that we conduct these joint exercises. They continue to go on."

The annual Max Thunder air exercises are running from May 14-25.

The Pentagon said the drills enhance the US-Korean alliance's ability to defend South Korea and boost interoperability and readiness between the two militaries.

"While we will not discuss specifics, the defensive nature of these combined exercises has been clear for many decades and has not changed," the Pentagon said in a statement.