* First session paves way for ministerial-level meeting
* Officials say discussions to focus on reopening commercial projects
* Meeting follows agreement at U.S.-China summit to persuade the North to denuclearise
North and South Korea opened their first official talks in two years on Sunday at a border village "without argument", the South said, building on an easing in tensions from nearly daily threats two months ago of impending nuclear war.
The meeting in Pammunjon, where the armistice was signed in the 1950-53 Korean War, was taking place hours after U.S. President Barack Obama and Chinese leader Xi Jinping agreed at a summit that the North had to abandon its nuclear programme.
The hour-long morning session appeared to pave the way for ministerial-level discussions next Wednesday. Such a meeting would be the first such encounter in more than six years.
A spokesman for the South's Unification Ministry, said the two sides discussed technical issues for the ministerial meeting, including the venue and size of delegations.
"After the morning meeting, we both agreed to keep discussing," Kim Hyung-suk told reporters at the ministry in Seoul.
"And the atmosphere of today’s meeting, as both South and North Korea have come to the meeting table after some time...was such that the talks have gone smoothly without any argument."
The meeting was to proceed through the afternoon, he said.
There was no immediate comment on the talks from the North.
Before the talks got underway, officials said they would focus on normalising commercial projects, including the Kaesong Industrial Zone just inside North Korea, closed in early April, and reuniting families still separated 60 years after the war.
North Korea's overture to hold discussions reversed months of bellicose rhetoric after the United Nations imposed toughened sanctions against the North in response to its third nuclear test in February. The North also reopened a Red Cross hotline with South Korea last week.
U.S., CHINA FIND COMMON GROUND
At their informal summit in the California desert, Obama and Xi found common ground on Korth Korea, whose belligerent rhetoric, nuclear tests and missile launches have frustrated Beijing, its only major diplomatic and financial ally.
White House National Security adviser Thomas Donilon said the two leaders "agreed that North Korea has to denuclearise, that neither country will accept North Korea as a nuclear-armed state". The two sides, he said, would "would work together to deepen cooperation and and dialogue to achieve denuclarisation".
U.S. officials came away from the meeting believing that China was ready to work more closely with the United States, but offered no specific measures to be taken.
North Korea has made plain that it has no intention of giving up its nuclear programme, with it describes as its "treasured sword". For weeks, it denounced exercises conducted by the militaries of the South and the United States, which maintains 28,000 troops south of the heavily militarised border.
At the height of the tensions in early April, North Korea withdrew its 53,000 workers at the Kaesong industrial zone, the last major joint project, and suspended operations. South Korea pulled out of its workers from the zone in early May.
Tensions eased after North Korea sent one of its top military officials to China last month. Choe Ryong-hae, an envoy of 30-year-old leader Kim Jong-un, said North Korea was willing to take steps toward peace and stability.
The last talks between military officials of the North and South took place in February 2011 -- in the aftermath of North Korea's shelling of Yeonpyeong Island in 2010, in which two marines and two civilians died.
Little progress was reported at those talks.