The plan would see North Korea suspend its ballistic missile programme and the US and South Korea simultaneously call a moratorium on large-scale missile exercises, both moves aimed at paving the way for multilateral talks.
Taking a major step in its missile programme, North Korea on Tuesday test launched an intercontinental ballistic missile that some experts believe has the range to reach the US states of Alaska and Hawaii and perhaps the US Pacific Northwest.
North Korea says the missile could carry a large nuclear warhead.
The missile test is a direct challenge to US President Donald Trump, who has vowed to prevent North Korea from being able to hit the US with a nuclear missile.
He has frequently urged China to press the isolated country's leadership to give up its nuclear programme.
Haley said the US would propose new UN sanctions on North Korea in coming days and warned that if Russia and China did not support the move, then "we will go our own path". She did not give details on what sanctions would be proposed, but outlined possible options.
"The international community can cut off the major sources of hard currency to the North Korean regime. We can restrict the flow of oil to their military and their weapons programmes. We can increase air and maritime restrictions. We can hold senior regime officials accountable," Haley said.
Diplomats say Beijing has not been fully enforcing existing international sanctions on its neighbour and has resisted tougher measures, such as an oil embargo, bans on the North Korean airline and guest workers, and measures against Chinese banks and other firms doing business with the North.
"Much of the burden of enforcing UN sanctions rests with China," Haley said.
China's UN ambassador, Liu Jieyi, told the Security Council meeting that the missile launch was a "flagrant violation" of UN resolutions and "unacceptable". "We call on all the parties concerned to exercise restraint, avoid provocative actions and belligerent rhetoric, demonstrate the will for unconditional dialogue and work actively together to defuse the tension," Liu said.
The US has remained technically at war with North Korea since the 1950-53 Korean conflict ended in an armistice rather than a peace treaty. Tensions have risen sharply after North Korea conducted two nuclear weapons tests last year and carried out a stream of ballistic missile tests.
North Korean leader Kim Jong Un said the ICBM test completed his country's strategic weapons capability that includes atomic and hydrogen bombs, the state KCNA news agency said.
Pyongyang will not negotiate with the United States to give up those weapons until Washington abandons its hostile policy against the North, KCNA quoted Kim as saying.
Russia and China both share a land border with North Korea and have been involved in past efforts to try to calm tensions between Pyongyang and the West.
Moscow and Beijing used the same joint declaration on Wednesday to call on Washington to immediately halt deployment of its Thaad anti-missile system in South Korea, a move Washington says is necessitated by the North Korean missile threat.
The statement said Washington was using North Korea as a pretext to expand its military infrastructure in Asia and risked upsetting the strategic balance of power in the area.
"The deployment ... of Thaad will cause serious harm to the strategic security interests of regional states, including Russia and China," the statement said.
Russia's deputy UN envoy said yesterday that military force should not be considered against North Korea and repeated the call for a halt to the deployment of Thaad.
He also said that attempts to strangle North Korea economically were "unacceptable" and that sanctions would not resolve the issue.
The US military, meanwhile, assured Americans that it was capable of defending the US against a North Korean ICBM.
Pentagon spokesman Navy Captain Jeff Davis noted a successful test last month in which a US-based missile interceptor knocked down a simulated incoming North Korean ICBM.
