SEOUL, South Korea (AP) - A North Korean envoy on Friday condemned Japan's imposition of economic penalties in response to the North's missile tests and warned that Tokyo's move could have “catastrophic effects.”

The warning came as South Korea's defense minister said Pyongyang could have another long-range missile at a launch site but does not appear close to firing it, and a U.S. envoy said the United States and China had agreed to work together to restore calm in the region.

Following North Korea's test-firing Wednesday of seven missiles into the Sea of Japan, the Japanese government barred a North Korean ferry from Japanese ports and imposed other measures that stop short of full-scale economic sanctions. Also, South Korea said it will delay food and fertilizer shipments to North Korea, and had turned down a proposal by the North to hold military talks this week.

Song Il Ho, the North Korean envoy in charge of talks on restoring relations with Japan, said in Pyongyang that the Japanese penalties were provocative, according to the APTN television agency.

“It can be said that the DPRK-Japan relations have come to a confrontational stage,” Song said at a news briefing.

“They deteriorated more than the DPRK-U.S. relations.” DPRK stands for North Korea's official name, the Democratic People's Republic of Korea.

Without elaborating, Song said the North would respond to pressure with strong action.

“As Japan is showing its denunciation as action, we cannot but take a stronger response in other forms,” he said. “Catastrophic effects will arise.”

In Tokyo, Japan's Chief Cabinet Secretary Shinzo Abe reacted sharply. “The comments are extremely regrettable, and anger me,” he said. “They'd better think carefully who caused such relations in the first place.”

“North Korea needs to understand that unless these problems are solved it will not be able to resolve the economic, food and energy problems it currently faces.”

Abe called for international efforts to send a strong message and pressure to persuade North Korea to not conduct any more launches.

Meanwhile, South Korean Defense Minister Yoon Kwang-ung said intelligence shows the North may have moved two long-range Taepodong-2 missiles to the launch site before it test-fired what was believed to be a Taepodong and six other, shorter-range missiles. The second Taepodong may still be at the site, but Yoon said there was no sign it was near the launch pad, according to the Yonhap news agency.

Yoon was quoted by Yonhap as saying there apparently was a technical problem with the North's Taepodongs and that further launches would likely be delayed until the glitch is resolved.

He also said that a North Korean boat that observed the missile launches had left the area - further suggestion that more immminent launches are unlikely.

The Taepodong is designed to reach as far the United States, according to U.S. officials. But on Wednesday, what appeared to be a Taepodong broke up less than a minute after takeoff and fell into the sea.

In Beijing, U.S. Assistant Secretary of State Christopher Hill, dispatched to the region in the wake of Wednesday's missile barrage, said China obviously opposed the launches. He said senior Chinese diplomats had told him that Beijing had contacted Pyongyang after the launches, though they did not provide details on what was said.

“They were very clear in their views of the North Korean missile launches, very clear that they have no interest in seeing this happen and do not regard this in anyway positively,” Hill said before departing for South Korea.

Hill said that he and the Chinese agreed that the two governments must work “to deal with the situation,” curb further North Korean provocations and persuade Pyongyang to return to regional negotiations on its nuclear program.

China - North Korea's staunchest ally and a source of oil and other economic assistance - is seen as key to getting Pyongyang to halt missile tests and resume stalled negotiations over its nuclear weapons programs.

Washington has urged Beijing to use the most leverage possible with North Korea. So far, China's efforts have been mostly limited to diplomatic appeals.

North Korea had proposed Monday that it meet with South Korean officials Friday at the border village of Panmunjom to arrange talks between generals aimed at reducing tension along the world's most heavily fortified border.

“Our side judged that it is not an appropriate time,” the South Korean Defense Ministry said in a statement Friday. “We notified the North that we would propose a date at an appropriate time later.”

The two sides held their last high-level military talks in May, but failed to produce any agreement because of a dispute over their marine border.

South Korea had been taking a relatively soft approach with Pyongyang, shelving earlier criticism of the missiles and insisting on maintaining ties with the North developed in recent years.

Yonhap quoted Choe Myong Nam, councilor at the North's mission to the U.N. in Geneva, as saying that Wednesday's launches were successful and could be continued, echoing an earlier statement by North Korea's Foreign Ministry.

“It's an unfair logic to say that somebody can do something and others cannot. The same logic applies to nuclear possession,” Choe said. The missile launches are “not intended to strike anyone and it's the North position that missile launches could be continued,” he said.

South Korea ordered two of its airlines to avoid a flight route near the path of the missiles until July 11.

In Washington, President Bush expressed support for a draft U.N. Security Council resolution, offered by Japan, to sanction North Korea for the launches. China and Russia have shown little interest in sanctions, saying diplomacy remains the only way to resolve the dispute.