US officials want to step up covert actions to stall Iran's alleged nuclear arms efforts, "in a tacit acknowledgment that the diplomatic initiatives with European and Asian allies have failed to curtail the programs," the daily said.
Meanwhile "North Korea now probably has enough weapons-grade plutonium to test a weapon in the future," despite toughened sanctions and several rounds of six-nation talks aimed at curtailing such efforts, the Times said.
The assessment comes from a new classified intelligence report, described to the Times by people who read it, which "appears to have been written far more cautiously than the National Intelligence Estimate that erroneously described advanced weapons programs in Iraq."
North Korea is thought to have "completely reprocessed" all of its weapons-grade plutonium, according to nonproliferation expert Gary Samore.
"They had a huge window of opportunity when we were invading Iraq, and they appear to have made maximum use of it," he told the Times.
Furthermore, both the Iranian and North Korean weapons programs are increasingly self-sufficient thanks to aid they received from Pakistani scientists, the daily said.
The architect of Pakistan's nuclear program Abdul Qadeer Khan confessed in February that he had sold nuclear technology to North Korea, Iran and Libya, confirming what experts have called the world's worst nuclear proliferation scandal.