Tensions with nuclear-armed North Korea have risen this year following the sinking of a South Korean warship in March that the U.S. and its allies blamed on a torpedo attack. President Barack Obama dispatched his envoy on the country, Stephen Bosworth, to Asian capitals this week after reports by a U.S. scientist that North Korea had revealed to him a ?stunning? new uranium-enrichment plant.
The yen and Korean won weakened against the dollar, U.S. stock futures fell and Treasury futures rose as investors sought safe-haven investments following the report.