Worries mounted on Friday that North Korean leader Kim Jong Il was planning a second underground nuclear test. Such a move would further isolate Pyongyang and could also strengthen the hand of United States Secretary of State Condoleezza Rice as she lobbies her Asian counterparts to rigorously enforce United Nations sanctions -- but it would also mean that Kim Jong Il was intent on acting defiant.

In a Tuesday report, NBC News cited an unnamed American official who said the North Koreans had already informed their longtime allies in China of the plan. A new test could be imminent simply “because the first one failed,” according to Joseph Bermudez, a researcher at Jane’s Defence Weekly in Britain.

International tensions are high. Following a meeting of European Union foreign ministers in Luxembourg on Tuesday, Germany's Frank-Walter Steinmeier warned that any attempt at follow-up tests would be seen by the EU as "a renewed and irrevocable provocation." In a joint statement, the EU foreign ministers chastised Pyongyang for violating non-proliferation agreements -- a move that could ultimately start an arms race in the region and serves to "reinforce (North Korea's) isolation" while doing "nothing to help the miserable situation of the North Korean people."

The UN passed resolution 1718 on Saturday, aiming to dismantle North Korea's nuclear program. The resolution includes a sanctions regime to prevent Pyongyang from obtaining more materials to produce weapons of mass destruction. North Korea's leader -- no stranger to bellicose language -- called any attempt to impose those sanctions a "declaration of war."

Key, of course, is whether the resolution will be enforced. While John Bolton continues to work the halls of the UN, US Secretary of State Condoleezza Rice is off to lobby her Asian counterparts to rigorously enforce the sanctions. She also wants to reassure Japan and South Korea that they should stay under America's protective umbrella rather than seek their own weapons.

Her biggest challenge, though, will be China. Beijing has already ordered the inspection of trucks and cargo crossing the Chinese border into North Korea, but its UN Ambassador indicated Monday that officials would not intercept or board ships. Fearing a possible collapse of Kim Jong Il's government, China wants to avoid raising tensions higher than they already are.

North Korea's first nuclear test  doesn't speak highly of China's ability to reign in its renegade neighbor. The incident represented a huge diplomatic failure for Beijing, which spearheaded the six-party talks aimed at bringing North Korea's nuclear program to a halt. Still, China carries a big stick: It's responsible for more than half of North Korea's trade, according to South Korea's state-run trade agency (KOTRA). Either Kim Jong Il doesn't think Beijing will use that stick, or he simply doesn't care.

Europe Plans Iran Resolution

In a separate development on Tuesday, European foreign ministers said they would push for limited sanctions against Tehran over its refusal to abandon efforts to create enriched uranium that could be used to build a nuclear weapon. Following months of failed diplomacy and Iran's resolute stance, the EU said it would seek to impose sanctions on individuals and materials involved in the enrichment program.

"The Iranians' refusal leaves us with no choice but to take the Security Council route," said French Foreign Minister Philippe Douste-Blazy.

The six countries that initially backed an EU incentives package aimed getting Tehran to drop its enrichment program -- the US, Russia, China, Britain, France and Germany -- were expected to begin work on a sanctions resolution at the UN on Wednesday.