There will be many opportunities to explore this and other diplomatic options in policy towards North Korea.
In public, and for now, it's unlikely that the US will signal any easing of its policy towards North Korea.
In his retirement Mr Roh criticised his successor's policies towards North Korea.
Among some South Koreans, there are lingering doubts as to whether the Chinese might have ambitions towards North Korea, should North Korea collapse.
Japanese hostility towards North Korea has risen since the North's admission last September that it kidnapped 13 Japanese citizens in the 1970s and 1980s.
Clinton and George W. Bush adopted appeasement policies towards North Korea.
Leftist critics of President Bush's "aggressive" policy towards North Korea blanched when he had the temerity to declare that North Korean leader Kim Jong-Il operated concentration camps.
We have consistently applied our principled approach towards North Korea.
WHITEHOUSE: President Obama and President Lee Press Availability
But ever since a preliminary investigation of the Cheonan's salvaged stern concluded that the blast did not come from on board the vessel, suspicions have turned towards North Korea.
Diplomats are discussing a draft resolution that would outline initial steps towards ending North Korea's nuclear weapons program.
It would be better to channel energies towards persuading North Korea to re-engage with the six-party process meant to get it to scrap its nuclear programmes and to bring about peace on the divided Korean peninsula (the talks have been stalled since the autumn, when North Korea refused to allow its nuclear declaration to be properly verified).
"We also agreed that a path is open to North Korea towards the resumption of talks and improved relations with the United States, Japan and Republic of Korea through dialogue, " a statement said.
At the end of last week Japan sent two of its most modern warships to the Sea of Japan with orders to shoot down any missiles fired by North Korea towards the Japanese islands.
BBC: UN chief Ban: Korea crisis could become 'uncontrollable'
Mr Roh hopes he has nudged the debate inside the Bush administration towards further direct talks with North Korea.
For the South Korean leader, the main consideration is negotiations with North Korea, towards which he would like Mr Bush to take a softer line.
The country's food crisis has its roots in atrocious farm productivity, the high international price of grain, and an embargo on much food aid because of North Korean belligerence towards South Korea in recent years.
ECONOMIST: Food and stability in North Korea: Deprive and rule | The
Observers fear North Korea is working towards creating a nuclear device small enough to fit on a long-range missile.
Vietnam is also edging towards becoming an important intermediary between North Korea (with which it has unusually good relations) and the outside world.
After last month's agreement on steps towards ending its nuclear programme, North Korea started bilateral talks on normalising relations with both America and Japan.
"North Korea must understand that belligerence towards its neighbors and defiance of the international community are signs of weakness, not strength, " Gibbs' statement said.
Importantly, the trip takes place at a time when Chinese diplomatic pressure is on North Korea to be less belligerent towards the South, and Chinese influence in the North is growing.
People's Daily Overseas Edition quotes unnamed experts playing down North Korea's hostile reaction towards an ongoing US-South Korean military drill as a "bluff" aimed at securing a peace agreement with the US. They dismiss the likelihood of war or a possible shelling attack by Pyongyang.
Over the past four years, the Obama administration's posture on North Korea was also dictated by former South Korean president Lee Myung-bak's hardline stance towards the North.
There have been reports that when North Korea test-fired a missile into the sea towards Japan last month, China briefly shut off its supply of oil to the country.
America says it will begin the process of removing North Korea from its list of countries that are considered to sponsor terrorism and move towards lifting trade sanctions against the North.
And also, President Obama and I agreed that we will of course work together in order to condemn North Korea at the United Nations, but also at the same time, we will work towards this very important global objective and that is to stop nuclear weapons proliferation.
WHITEHOUSE: President Obama & South Korean President Lee at G20 Summit
If North Korea gives up its pursuit of nuclear weapons and missile development, and instead chooses a path towards peace and cooperation, our two countries will work together, along with the international community, to help improve the lives of the people in North Korea and provide necessary assistance that will help North Korea open up a new era.
WHITEHOUSE: President Obama and President Lee Hold a News Conference
应用推荐