WASHINGTON, July 2 (IslamOnline & News Agencies) - The United States Tuesday rescinded an offer to send a high-level envoy to Pyongyang next week following a naval clash between North and South Korea. Meanwhile, North Korea accused the U.S. of orchestrating the naval clash Saturday, to “drive a wedge” between the two Koreas, news agencies reported.

U.S. State Department spokesman Richard Boucher said that Washington informed Pyongyang that the atmosphere for a resumption of U.S.-North Korean dialogue became "unacceptable" as a result of Saturday's clash, reported Agence France-Presse (AFP).

That came after a Pyongyang Foreign Ministry spokesman said Tuesday that Saturday's skirmish erupted after South Korean warships intruded into the North's territorial waters and opened fire at North Korean navy vessels, according to The Times of India newspaper.

South Korea said two North Korean patrol boats crossed the disputed sea frontier, known as the northern limit line (NLL), and one opened fire after ignoring warnings from the South Korean navy.

The battle in the Yellow Sea off the west coast of the Korean peninsula left four South Korean sailors dead, one missing and 19 wounded from a South Korean patrol boat that was hit and sunk.

The spokesman, quoted by the North's official Korean Central News Agency, noted that the NLL was not mentioned in the armistice agreement that ended the 1950-53 Korean War and was drawn up by the U.S.-led United Nations forces.

North Korea declared its own sea border which runs several km south of the NLL.

"The intrusion of many warships and fishing boats of the South side deep into the territorial waters of our side under the pretext of such (a) bogus line was a grave act of aggression," the spokesman said.

He said the United States should be held responsible for such intrusions, noting that the United States commands allied South Korean forces together with some 37,000 U.S. troops stationed in the South.

He said the NLL was "the basic cause of the incident."

"All facts clearly prove that the incident was orchestrated by the United States to drive a wedge between the North and South of Korea because it was displeased with the progress made in the inter-Korean relations and has put a brake on it from the outset," he said.

"The issue of sovereignty is quite different from the issue of dialogue.

"We will in the future, too, not pardon anyone encroaching upon the sovereignty of the DPRK (North Korea) but take a decisive retaliatory step for self-defense by all means," he said.

However, U.S. officials stressed that Washington remained interested in resuming a dialogue with North Korea despite the complications of the clash and the fact that Pyongyang had not responded promptly to the offer which was extended last week.

"We are not prepared to send a delegation at this time in light of the lack of response to our proposal for discussion and the naval incident," one U.S. official told AFP on condition of anonymity.

A second official, also speaking on condition of anonymity, told AFP that U.S. officials informed North Korea Monday that U.S. Assistant Secretary of State for East Asian and Pacific Affairs James Kelly would not be traveling to Pyongyang between July 10 and 12 as had been envisaged by the offer.

"We told them yesterday (Monday) that given their lack of response we were not in a position to go in the time frame we had talked about and in addition that the atmosphere was soured by the incident," the second official said.

"We did say we are still willing to talk when we think its appropriate but we told them that next week's dates are off the table and there are no new ones on the table," the official said.

The official said there was no discernible reaction from Pyongyang to the withdrawal of the offer - communicated by U.S. diplomats on the telephone to North Korean diplomats at the United Nations.

However, the official said that around the same time the call was made, the North Korean Foreign Ministry blamed the United States for the clash, a charge vehemently denied by the U.S. State Department.