U.N. nuclear watchdog chief Mohamed ElBaradei said on Monday more talk and deeper trust were needed to defuse nuclear disputes with North Korea and Iran, and he urged Washington to stick to dialogue with both states.

ElBaradei, head of the International Atomic Energy Agency, said he hoped North Korea, which expelled IAEA monitors last week, would soon invite them back and avoid confrontation, and that Iran would reciprocate recent friendly U.S. overtures by opening its nuclear activities to broader inspections.

"The only way to resolve these issues is not through flexing muscles," said ElBaradei, referring to North Korea and Iran. He was speaking at a news conference in Beijing during an international meeting on nuclear energy policy.

ElBaradei praised the Barack Obama''s administration for backing dialogue with Tehran and holding out the hope of renewed six-party nuclear disarmament talks with Pyongyang, which recently launched a long-range rocket, drawing U.N. censure.

"I''m optimistic about the new environment," ElBaradei said of Obama''s opening to Iran and calls to eventually end nuclear arms.

The IAEA cannot directly broker negotiations over the nuclear disputes with North Korea and Iran, both once labeled members of an "axis of evil" by President George W. Bush. But ElBaradei''s comments may bolster calls for patience and negotiations in both hotspots.