Hill was in Seoul on a tour of regional capitals in to coordinate the international response to the North's test-firing of seven missiles on Wednesday. The tests sparked widespread criticism of the regime, but the U.S. is split with China and Russia over whether to punish Pyongyang.
Beijing, where Hill held meetings on Friday, has floated the idea of the members of the six-party talks - the two Koreas, China, Russia, Japan and the U.S. - hold an informal meeting on the standoff. Pyongyang is currently boycotting the formal six-nation talks held in Beijing.
Hill said the U.S. and South Korea backed the idea.
"As many of you know, the Chinese have talked about putting together a six-party informal, and we both support that and we think that all countries are prepared to come to that informal meeting," Hill told reporters.
The U.S. envoy, who was to meet South Korean Foreign Minister Ban Ki-moon later Saturday and head to Japan on Sunday, dismissed a North Korean demand that the U.S. drop its crackdown on the regime's alleged financial crimes, such as money-laundering and counterfeiting.
"This is not a time for so-called gestures of that kind," Hill said when asked by reporters for reaction to the North Korean demand. "We have a country that has fired off missiles in a truly reckless way that affects ... regional security."
North Korea has boycotted talks for months in protest on the crackdown, and has refused to return until the punitive measures are lifted. Washington, however, has argued that the two issues are separate and should not be linked.
Hill, speaking after a meeting with Chun Young-woo, South Korea's top negotiator in international nuclear talks, also insisted the two allies would not be split over their response to the missile tests.
"What we're not going to do is allow the ... missile launches to divide us," Hill told reporters. "These missile launches have actually brought us closer together and we're going to work very closely together in the weeks ahead."
The North in recent days has remained defiant, defending its right to test missiles and saying the launches could continue. Pyongyang has also threatened to take "stronger" measures against anyone who tries to stop further tests.
North Korean media devoted coverage Saturday to the 12th anniversary of the death of President Kim Il Sung, the national founder who was succeeded by his son, Kim Jong Il, in communism's first hereditary transfer of power. The late Kim, who died on July 8, 1994 at the age of 82, is revered in the North and his portrait adorns government buildings and many homes.
Meanwhile, a draft U.N. resolution on sanctions against Pyongyang could be put to a vote next week, as regional powers moved to coordinate their response.
South Korea's Yonhap news agency early Saturday quoted a North Korean diplomat as saying North Korea is willing to return to the six-nation talks if it is allowed to withdraw its money frozen in accounts of a bank blacklisted by the United States.
Han Song Ryol, deputy chief of North Korea's mission to the United Nations in New York, made the remark, renewing the North's long-standing demand that the U.S. lift financial restrictions imposed on a Macau bank for allegedly aiding the North's illicit activities.
"Removing the freeze on Macau funds is the minimum threshold to resumption of talks," Han said. "If there is such a will, then how we talk, whether bilaterally or through six-party talks, is not important."
Chun, the South Korean negotiator, said in Seoul that North Korea's demand for the financial restrictions to be lifted was "unrealistic" and urged the North not to link the issue to the six-party nuclear talks.
Japan and the United States have led an effort for the U.N. to impose sanctions, but China and Russia have called for softer measures. On Friday, Japan circulated a draft resolution that would order countries to "take those steps necessary" to keep the North from acquiring items that could be used for its missile program. Diplomats said the U.N. Security Council would take up the issue on Monday.
South Korea, which has worked for warmer ties with Pyongyang since a 2000 North-South summit, has withheld aid shipments and rejecting a Northern request for military talks, but also announced it would hold Cabinet-level meetings with the North next week.
Unification Minister Lee Jong-seok said Seoul would hold off on plans to send 500,000 tons of rice and 100,000 tons of fertilizer to North Korea.
The North had requested 450,000 tons of fertilizer this year, of which the South has already shipped 350,000 tons. Pyongyang, which is largely dependent on handouts of food and other supplies to maintain its poverty-stricken population, has also asked for 500,000 tons of rice.
By JAE-SOON CHANG