UNITED NATIONS (Reuters) - The United States presented a draft Security Council resolution on Thursday it negotiated with China that would dramatically tighten existing restrictions on North Korea after its Jan. 6 nuclear test and create the toughest U.N. sanctions regime in over two decades.

North Korean leader Kim Jong Un (C) watches a long range rocket launch into the air in North Korea, in this photo released by Kyodo February 7, 2016. REUTERS/Kyodo

The draft, seen by Reuters, would require U.N. member states to conduct mandatory inspections of all cargo passing through their territory to or from North Korea to look for illicit goods. Previously states were only required to do this if they had reasonable grounds to believe there was illicit cargo.

The United States used the nearly two months of bilateral negotiations that at one point involved President Barack Obama and his Chinese counterpart, diplomats said, to win China’s support for unusually tough measures intended to persuade its ally North Korea to abandon its atomic weapons program.

The proposal would close a gap in the U.N. arms embargo on Pyongyang by banning all weapons imports and exports.

There would also be an unprecedented ban on the transfer to North Korea of any item that could directly contribute to the operational capabilities of the North Korean armed forces, such as trucks that could be modified for military purposes.

Other proposed measures include a ban on all supplies of aviation and rocket fuel to North Korea, a requirement for states to expel North Korean diplomats engaging in illicit activities, and blacklisting 17 North Korean individuals and 12 entities, including the National Aerospace Development Agency or ‘NADA’, the body responsible for February’s rocket launch.

U.S. Ambassador to the United Nations Samantha Power told reporters the new measures, if approved, would be “the strongest set of sanctions imposed by the Security Council in more than two decades.”

Several council diplomats predicted a Saturday meeting to adopt the draft but Russian deputy U.N. ambassador Petr Iliichev told Reuters Moscow needed time to study the draft and the earliest likely vote would be next week. The draft was the result of seven weeks of tough negotiations between the United States and China, North Korea’s neighbor and main ally.

“This is a very robust resolution,” a U.S. official said on condition of anonymity. “Clearly this took a long time ... it was a difficult process.”

DIFFERENCES BETWEEN CHINA, U.S.

North Korea has been under U.N. sanctions since 2006 because of its multiple nuclear tests and rocket launches.

China and the United States had differed on how strongly to respond to Pyongyang’s most recent test, with Washington urging harsh punitive measures and Beijing emphasizing dialogue and milder U.N. steps confined to non-proliferation.

The Global Times, an influential Chinese tabloid published by the ruling Communist Party, said in an editorial that North Korea “deserves the punishment” of new sanctions, but China should “cushion Washington’s harsh sanctions to some extent.”

“China insists the sanctions should focus on striking North Korea’s ability to continue developing nuclear weapons. It is the fundamental difference between China’s policy and that of the U.S., South Korea and Japan. China holds unswerving goodwill toward North Korea, which Chinese society hopes Pyongyang can understand,” it said.

Diplomats said a sharp tightening of restrictions was necessary since Pyongyang has proved its determination to flout at all costs attempts at constraining its nuclear and missile programs.

They said they hoped the latest measures would make it harder for North Korea to continue with that policy, keeping up the pressure on the country’s leadership without making the country’s impoverished population any poorer.

“Pyongyang has prioritized the pursuit of these massively expensive programs over absolutely everything else,” the U.S. official said. “So is New York action going to automatically convince the regime’s leaders to cease? I think we’re realistic on that point.”

However, he added that “this resolution will be felt, it will have an impact ... The DPRK (North Korea) have never been subject to the kind of pressure that is in the resolution.”

Power said the measures were aimed at the country’s leadership, and “careful not to punish the North Korean people.”

In Beijing, Chinese Foreign Ministry spokeswoman Hua Chunying told a regular press briefing on Thursday: “We hope and believe this new resolution can help effectively constrain North Korea from further developing its nuclear missile program”.

There will also be further restrictions aimed at making it more difficult for North Korea to press ahead with its nuclear and missile programs. Pyongyang is currently banned from importing and exporting nuclear and missile technology and is not allowed to import luxury goods. The list of banned items will be expanded.

The U.S. official said one of five annexes to the resolution lists 31 ships owned by North Korean shipping firm Ocean Maritime Management Company Limited, which will be blacklisted.

Also new, countries will be required, not just encouraged, to freeze the assets of North Korean entities linked to Pyongyang’s nuclear or missile programs and to prohibit the opening of new branches or offices of North Korean banks or to engage in banking correspondence with North Korean banks.