South Korea’s first rocket launch Tuesday failed to push a satellite into its orbit but the flawed mission may still anger rival North Korea, coming just months after the communist nation’s own launch drew international condemnation.

The failure dealt a blow to Seoul’s quest to become a regional space power. It comes against the complex backdrop of relations on the Korean peninsula – and recent signs that months of heightened tension over the North’s nuclear program may be easing.

Also Tuesday, a South Korean newspaper reported that North Korea has invited top envoys of President Barack Obama for the first nuclear negotiations between the two countries under his presidency, but Washington quickly said it has no plans to send the envoys to Pyongyang.

The North gave no immediate reaction to the rocket launch but has said it will watch to see if the U.S. and regional powers refer the matter to the U.N. Security Council. A launch by North Korea in April was suspected to be a disguised test of long-range missile technology and drew a U.N. rebuke.

The North regarded the reaction as discriminatory, saying it fired a satellite into space, although experts say no such satellite has been detected. The North, unlike the South, is banned from any ballistic activity by Security Council resolutions as part of efforts to eliminate its nuclear and long-range missile programs.

U.S. State Department spokesman Ian Kelly spoke in support of South Korea, saying it has pledged to develop rockets for peaceful purposes only, and that there was no indication the launch was “in any way inconsistent with its international obligations and international commitments.”

The launch Tuesday was South Korea’s first involving a rocket from its own territory. It was a two-stage Naro rocket whose first stage was designed by Russia. It lifted off from South Korea’s space center on Oenaro Island, about 290 miles (465 kilometers) south of Seoul.

The rocket was carrying a domestically built satellite aimed at observing the atmosphere and oceans. A South Korean official said they could not trace the satellite in orbit after it separated from the rocket.

“We could not locate our satellite. It seems that communications with the satellite scheduled on Wednesday are unlikely to happen,” Science Ministry official Yum Ki-soo told The Associated Press late Tuesday.

He said South Korean and Russian scientists were analyzing data to try to determine the cause of the failure.

Russia’s Interfax-AVN news agency, citing an unidentified Russian space industry source, said the satellite never reached orbit and problems occurred in the South Korean-built second stage of the rocket.

In Moscow, an official at the Russian space agency, Roscosmos, declined to comment on the fate of the satellite. In joint statements, Roscosmos and the state-controlled Khrunichev company, which made the rocket’s first stage, said that the first stage of the rocket operated as planned.

South Korean President Lee Myung-bak called the launch a “half success.”

“We must further strive to realize the dream of becoming a space power,” Lee said, according to his office. Among Asian countries, China has conducted a manned space flight, and Japan and India have also sent rockets carrying satellites into space.

North Korea said it would be “watching closely” for the international response to Seoul’s launch after its own launch drew what it maintains was unfair international condemnation.

South Korean officials said it is inappropriate to compare their launch with the North’s because Seoul’s is for peaceful purposes, in accordance with its membership in international treaties, and was carried out with transparency. “We’ve been doing this openly,” Defense Ministry spokesman Won Tae-jae told reporters.

Kim Tae-woo, a senior analyst of the Korea Institute for Defense Analyses, said that despite the North’s stance, Tuesday’s launch is unlikely to have major implications on inter-Korean relations.

In recent weeks, the North has become markedly more conciliatory toward both the United States and South Korea. Earlier this month, it freed two American journalists following a trip to Pyongyang by former President Bill Clinton. It has also freed a South Korean detainee, agreed to lift restrictions on border crossings with the South and resume suspended inter-Korean projects in industry and tourism.

Pyongyang also reportedly invited U.S. envoys for talks on its nuclear program. The invitation was extended to Stephen Bosworth, special envoy to North Korea, and nuclear negotiator Sung Kim, Seoul’s JoongAng Ilbo daily reported.

But in Washington, spokesman Kelly said Tuesday that neither Bosworth nor Sung Kim has plans to go to North Korea. He would not say explicitly whether any North Korean invitation was received.

Pyongyang has long sought direct negotiations with Washington about its nuclear program and other issues. The U.S. says it is willing to talk bilaterally to Pyongyang, but only within the framework of six-party talks involving the two Koreas, the U.S., China, Russia and Japan, which North Korea withdrew from in April. By KWANG-TAE KIM Associated Press Writer