HANOI - North Korea on Friday vowed a "physical response" to recent measures imposed by the United States in response to the sinking of a South Korean warship.

"There will be physical response against the steps imposed by the United States, militarily.

It is no longer the 19th century which... maintained the gunboat diplomacy," said Ri Tong Il, spokesman for the North Korean delegation at regional security talks in Hanoi.

He told reporters that Pyongyang "strongly condemns" fresh sanctions announced in Seoul on Wednesday by United States Secretary of State Hillary Clinton.

Clinton on Friday accused North Korea of embarking on a "campaign of provocative, dangerous behaviour" including the sinking of the South Korean warship Cheonan in March, which killed 46 sailors.

The US and South Korea have announced naval exercises, beginning on Sunday, in what they said is a bid to deter North Korea`s "aggressive" behaviour.

BDST: 1348 HRS, July 23, 2010