Reason for optimism on the Korean peninsula

North Korea did not retaliate as threatened after a South Korean military exercise that it had warned could lead to war.

At the same time, the North agreed to allow U.N. monitors access to its uranium-enrichment facility and take other steps that could defuse tension if implemented, including considering the formation of a military commission made up of representatives from the North, the South and the United States.

Those steps generated at least the possibility of rare optimism on the Korean peninsula, which has been gripped by anxiety since March.

The latest developments came amid a visit to North Korea by Bill Richardson, the former U.S. ambassador to the United Nations and current governor of New Mexico.

"Maybe we had a little impact with them," he said Monday of the North Korean leaders.

"I think they deserve credit for holding back," he said. "I think North Korea may be sending a signal that they're ready to re-engage after having behaved very negatively."

Most serious crisis on the Korean peninsula since 1953

New Mexico Gov. Bill Richardson provided North Korea with a series of proposals Saturday in what he described as a "good meeting" with the country's chief nuclear negotiator Kim Gye Gwan. 

Richardson told CNN’s Wolf Blitzer the situation "by all accounts right now is the most serious crisis on the Korean peninsula since the 1953 armistice which ended the Korean war."

Prior to this, Russia summoned the South Korean and US envoys over the live-fire drill planned by Seoul amid mounting tensions with North Korea. As a member-state of the six-party negotiations on the Korean peninsula crisis, Russia hosted the North Korean foreign minister last week in a bid to help find a way out of the escalating dispute.

South Korea announced that scheduled military drills likely would not be held this weekend due to an adverse weather forecast. The drills will be held only if the weather improves in the areas surrounding Yeonpyeong Island, South Korea's Joint Chiefs of Staff said.

The North Korean military threatened on Friday to strike back if South Korea goes ahead with its drill.