The United States is prepared to hold naval drills near the Korean Peninsula again to ensure security of South Korea, U.S. Secretary of State Hillary Clinton said on Friday.

"One measure of the strength of a community of nations is how it responds to threats to its members, neighbors, and region," Clinton said at the Association of Southeast Asian Nations (ASEAN) meeting in Hanoi, Vietnam.

"Here in Asia, an isolated and belligerent North Korea has embarked on a campaign of provocative, dangerous behavior, including its attack on the Republic of Korea," she continued.

"It is distressing that North Korea continues its threat and causes so much anxiety among neighbors and a larger region," Clinton said.

Earlier on Friday, North Korea threatened "physical response" to U.S. and South Korean military drills to be held July 25-28.

"There will be physical response against the steps imposed by the United States militarily," North Korean spokesman Ri Tong Il said, adding that the exercise will be "another expression of hostile policy" against North Korea.

"It is no longer the 19th century. The present century is one of peace and stability," Ri said.

Ri said the joint military drills threatened North Korean sovereignty and security on the Korean Peninsula and Asia as a whole.

Joint U.S.-South Korean military drills are due to be held in the Sea of Japan starting this weekend. Initially, the exercises were scheduled on June 8-11, however, they were postponed as the sides decided to wait for a UN resolution on the sinking of South Korea's Cheonan corvette.

"These are exercises that are designed to improve our coordination and training and capabilities with our South Korean allies," U.S. State Department spokesman Philip Crowley said. "They're not meant as a provocation."

The 1,200-ton South Korean warship sank near the disputed Northern Limit Line in the Yellow Sea on March 26, causing the loss of 46 lives. South Korea says it has proof that North Korea fired a torpedo at the vessel from a submarine, although Pyongyang denies the attack.

The UN Security Council condemned the incident and stressed the need to prevent similar attacks in the region, but did not place the direct responsibility on North Korea.

Earlier Clinton announced new sanctions on the country, following an investigation that linked the sinking of the Cheonan ship with Pyongyang.

HANOI, July 23 (RIA Novosti)