official@ (Adds Trump posts on Twitter, Japanese Prime Minister Abe, background)
* Trump to accept invitation to meet Kim -White House spokeswoman
* Meeting between Trump & Kim would be breakthrough in crisis
* Kim committed to denuclearization -South Korean security adviser
WASHINGTON, March 8 (Reuters) - President Donald Trump is ready to meet North Korean leader Kim Jong Un by May in response to Kim's invitation to hold the first-ever U.S.-North Korea summit, a South Korean envoy said, marking a potentially dramatic breakthrough in the North Korea nuclear standoff.
Kim has committed to "denuclearization" and to suspending nuclear or missile tests, South Korea's National Security Office head Chung Eui-yong told reporters at the White House after briefing Trump on South Korean officials' meeting with Kim on Monday.
White House spokeswoman Sarah Sanders said Trump "will accept the invitation to meet with Kim Jong Un at a place and time to be determined."
She added: "We look forward to the denuclearization of North Korea. In the meantime, all sanctions and maximum pressure must remain."
A meeting between Kim and Trump, who have exchanged bellicose insults in the past year that have raised fear of war, would be a major turnaround after a year in which North Korea has carried out a battery of tests aimed at developing a nuclear-tipped missile capable of hitting the U.S. mainland.
"I told him (Trump) that in our meeting that North Korean leader Kim Jong Un said that he's committed to denuclearization," Chung said. "Kim pledged that North Korea will refrain from any further nuclear or missile tests."
"He expressed his eagerness to meet President Trump as soon as possible," he said. "President Trump appreciated the briefing and said he would meet Kim Jong Un by May to achieve denuclearization."
Trump's aides have been wary of North Korea's diplomatic overtures because of its history of reneging on international commitments and the failure of efforts on disarmament by the administrations of President Bill Clinton, President George W. Bush and President Barack Obama.
Under Clinton in October 2000, then-U.S. Secretary of State Madeleine Albright held talks in Pyongyang with then-North Korean leader Kim Jong Il, the father of Kim Jong Un.
On Thursday night Trump took to Twitter with a series of posts putting the potential meeting with Kim in a positive frame.
"Kim Jong Un talked about denuclearization with South Korean Representatives, not just a freeze," said one post. And Trump added: "Great progress being made but sanctions will remain until an agreement is reached. Meeting being planned!"
JOINT MILITARY EXERCISES
Chung and National Intelligence Service chief Suh Hoon flew to Washington earlier on Thursday to explain North Korea's stance on possible future talks with Washington and the prospect of Pyongyang suspending nuclear tests if the security of the North's government is assured.
In what would be a key North Korean concession, Chung said Kim "understands that the routine joint military exercises between the Republic of Korea and the United States must continue." Pyongyang had previously demanded that such joint drills be suspended in order for any U.S. talks to go forward.
Trump in the past has derided the North Korean leader as a maniac, referred to him as little rocket man and threatened in a speech to the United Nations last year to "totally destroy" his country of 26 million people if it attacked the United States or one of its allies.
Kim had responded by calling the U.S. president a mentally deranged U.S. dotard.
Trump has also been scathing in his criticism of Kim and of previous U.S. administrations for not doing more to rein in the North Korean government.
Japanese Defense Minister Itsunori Onodera said on Friday North Korea must commit to abandoning nuclear development completely in order for meaningful talks to take place with Pyongyang. Japanese Prime Minister Shinzo Abe said the change in North Korea's attitude is the result of pressure from allies Japan, the United States and South Korea and others.
Daniel Russel, until last April the assistant secretary of state for East Asia and the Pacific, the most senior U.S. diplomatic position for Asia, noted there had still been no public comment from North Korea about the content of Mondays meeting.
"Lets hear from the North Koreans themselves what they are proposing and what they are willing to do. There is plenty of reason to be cautious, given their track record. Second, lets read the fine print. The North has made peace overtures in the past that did not hold up under scrutiny," Russell said.
Tensions over North Korea rose to their highest in years in 2017, and the Trump administration has warned that all options are on the table, including military ones, in dealing with Pyongyang, which has pursued its weapons programs in defiance of ever tougher U.N. sanctions.
Signs of a thaw emerged this year, with North and South Korea resuming talks and North Korea attending the Winter Olympics. During the Pyongyang talks this week, the two Koreas agreed to hold their first summit since 2007 in late April.
South Korean President Moon Jae-in has said sanctions should not be eased for the sake of talks and that nothing less than denuclearization of North Korea should be the final goal for talks.
China's foreign minister, Wang Yi, called on the United States and North Korea to hold talks as soon as possible, warning at a news briefing in Beijing on Thursday that things "will not be smooth sailing".
(Reporting Jeff Mason, David Brunnstrom and Matt Spetalnick in WASHINGTON and Christine Kim in SEOUL, additional reporting by Steve Holland in WASHINGTON, Ben Blanchard in BEIJING and Aaron Maasho and Kumerra Gemechu in ADDIS ABABA; Editing by Will Dunham, James Dalgleish, Grant McCool)