The United States said Sunday it has invited a top North Korean envoy to New York for "exploratory talks" on the possible resumption of the six-party negotiations on denuclearisation. Secretary of State Hillary Clinton said the North's vice foreign minister and former nuclear negotiator, Kim Kye-Gwan, would visit the US at the "end of next week". The invitation was announced after envoys from North and South Korea held unexpected talks in Indonesia on Friday, on the sidelines of an Asian security forum which Clinton attended alongside ministers from China and South Korea. "Following the first round of denuclearisation talks between the nuclear negotiators of the Republic of Korea and North Korea, the United States has invited North Korean Vice Foreign Minister Kim Kae-gwan to New York toward the end of next week," Clinton said in a statement. In a statement released to reporters as she left Indonesia after three days of intense engagement with East Asian foreign ministers, Clinton said Kim would meet with an interagency team of US officials. Their discussions would focus on the "next steps necessary to resume denuclearisation negotiations through the six-party talks", she said. "This will be an exploratory meeting to determine if North Korea is prepared to affirm its obligations under international and six-party talk commitments, as well as take concrete and irreversible steps toward denuclearisation," Clinton said. She said the United States had repeatedly affirmed its readiness to open talks with North Korea, but it was not prepared to offer any new concessions in order to re-start the stalled multilateral negotiations. "We do not intend to reward the North just for returning to the table," Clinton said. "We will not give them anything new for actions they have already agreed to take. And we have no appetite for pursuing protracted negotiations that will only lead us right back to where we have already been." South Korea's Yonhap news agency, citing diplomatic sources in Seoul, earlier Sunday reported that Kim would visit New York around Thursday. Kim will discuss the North's nuclear issues and possible resumption of US food aid with Stephen Bosworth, the US special envoy on North Korea, as well as other officials, it said. South Korean nuclear envoy Wi Sung-Lac and his counterpart from the North, Ri Yong-Ho, met for more than two hours at a luxury hotel in Bali on Friday. Both emerged saying they hoped to re-start the six-party talks. The South's foreign minister, Kim Sung-Hwan, then briefly met his North Korean counterpart, Pak Ui-Chun, on Saturday morning ahead of the regional security dialogue. Clinton said the United States was "encouraged" by the surprise talks but remained cautious on resuming the disarmament forum. North Korea had to improve North-South relations, she said, after recent incidents including the shelling of a South Korean island and alleged sinking of a South Korean warship. In a joint statement released Saturday, the United States, South Korea and Japan also said Pyongyang must "address" its secretive uranium enrichment programme before the talks could re-start. The six-party denuclearisation forum, grouping two Koreas, the US, Japan, China and Russia, has been deadlocked since the last meeting in December 2008. The impoverished communist state, believed to have enough plutonium for six to eight atomic bombs, stormed out of the talks in April 2009 and a conducted its second nuclear test a month later. The North also revealed an apparently operational uranium enrichment plant to visiting US experts last November, claiming it was for peaceful energy.