South Korea is to suspend food aid to the North because of its controversial missile tests, reports said.
Pyongyang tested seven missiles
Shipments of rice and fertiliser would be shelved until the missile "problem" was resolved, South Korea's Yonhap news agency quoted a top official as saying.
The move came as Japan presented the UN Security Council with a binding draft resolution calling for sanctions against North Korea.
Pyongyang has threatened more launches if it is subjected to foreign pressure.
The resolution, which urges North Korea to immediately stop developing, deploying and testing ballistic missiles and to return to talks on its nuclear programme, was presented by Japan's UN ambassador, Kenzo Oshima.
"We hope that it will be adopted when it is put to a vote with the broad unanimity of the council," Mr Oshima told reporters following the meeting.
It was crucial that the Security Council act "firmly, robustly and speedily", he stressed.
Japan wants swift action on the resolution, and has pushed for a vote as early as Saturday.
The full 15-member council was due to debate the resolution later on Friday, following a morning meeting of the permanent five members.
The draft is backed by the US and the UK, but opposed by two other permanent Council members, China and Russia, both of whom want a non-binding statement without the threat of sanctions.
"What matters most of all is for (North Korean leader) Kim Jong-il to see the world speak with one voice," US President George W Bush said during a press conference in Chicago.
"All of us said: 'Don't fire that rocket.' He not only fired one, he fired seven.
"Now that he has made that defiance, it's best for all of us to go to the UN Security Council and to say, loud and clear: 'Here are some red lines', and that's what we're in the process of doing."
US envoy Christopher Hill has meanwhile arrived in the South Korean capital, Seoul, for talks on the international response to the crisis.
"We should not have business as usual with a country that is firing missiles like this in this rather reckless way," Mr Hill told reporters as he arrived in Seoul after talks in Beijing.
South Korea is the North's biggest food aid donor, helping the impoverished North feed its people.
"We promised to ship 100,000 tonnes of fertiliser aid to the North but we will shelve it.
"We will also put off 500,000 tonnes of rice aid until any breakthrough is made in the missile issue," the AFP news agency quoted a South Korean official as saying.
But South Korea did say it intended to go ahead with cabinet-level talks next week.
Earlier, South Korean Defence Minister Yoon Kwang-ung played down reports the North was preparing to launch a second long-range missile.
The North tested seven missiles on Wednesday, one of which was a long-range Taepodong-2, believed to be capable of hitting Alaska.
Pyongyang described the tests as successful, despite the apparent failure of the Taepodong-2. All seven missiles landed in the Sea of Japan.
Mr Yoon was quoted by Yonhap as saying the North may have moved two Taepodong-2 missiles to its launch site in Musudan-ri, one of which was tested.
NORTH KOREAN MISSILE MOVES
1998: Tests long-range Taepodong-1 over Japan
1999: Agrees to moratorium on long-range tests
2003: Six-nation talks begin on N Korea's nuclear programme
2005: Six-nation talks stall
July 2006: N Korea launches seven missiles, including long-range Taepodong-2, which fails
But he said Japanese media reports that another missile was being prepared for launch were inaccurate, as the second missile was not yet assembled.
In Beijing, Mr Hill met Chinese Foreign Minister Li Zhaoxing as well as senior envoy Wu Dawei.
Mr Hill said some consensus had been reached.
"There is broad agreement on the fact that what (North Korea) did is really a provocative act, and that we all need to speak with one voice," Reuters news agency quoted him as saying.
North Korea has meanwhile demanded Japan immediately revoke measures it has already imposed in reaction to the missile launches - such as a six-month ban on a ferry service that provides a vital economic link for Pyongyang.