The United States on Wednesday rebuffed China's appeal for talks with North Korea, saying leader Kim Jong-Un was behaving irrationally and that it was reassessing its approach to dealing with Pyongyang.
China, Pyongyang's main ally, earlier called on North Korea to suspend its nuclear and missile activities in exchange for a halt to the annual US-South Korean military drills.
Foreign Minister Wang Yi said in Beijing that the proposal could help bring the United States and North Korea back to negotiations and avert what he termed a "head-on collision".
After a closed-door meeting of the UN Security Council, US Ambassador Nikki Haley said North Korea's actions called for a different response.
"We are not dealing with a rational person," Haley told reporters.
"If this were any other country, we would be talking about that and it wouldn't be an issue."
She described Kim as a "person who has not had rational acts, who is not thinking clearly."
"We are re-evaluating how to handle North Korea going forward," she added.
North Korea fired at least four missiles toward Japan on Monday, three of which splashed down in waters near Japan.
The Security Council met to discuss next steps to address North Korea's missile launches after Pyongyang said the latest tests were for a possible strike on US bases in Japan.
The US ambassador said "all the options are on the table" and did not rule out talks completely but she made clear that North Korea must first show a willingness to seek a diplomatic solution.
"We have to see some sort of positive action taken by North Korea before we can ever take them seriously," said Haley.
Her comments came as US Secretary of State Rex Tillerson prepares to visit Japan, South Korea and China starting next week, his first trip to the region, with talks to focus on North Korea.
China's proposal mirrored past North Korean offers that were rejected by the United States, which said Pyongyang had no right to demand concessions in return for abiding by UN resolutions.
Six sets of UN sanctions since Pyongyang's first nuclear test in 2006 have failed to halt its drive for what it insists are defensive weapons. It held its most recent nuclear test last September.
- Tensions over US-SKorea missile defense -
The council on Tuesday strongly condemned North Korea's latest ballistic missile launches in a statement unanimously adopted despite tensions with China over Washington's deployment of an advanced missile defense system in South Korea.
In Beijing, Wang continued China's hammering of the US Terminal High Altitude Area Defense (THAAD) system, repeating Beijing's "strong opposition" and calling on Seoul to "cease and desist."
THAAD is designed to intercept and destroy short and medium-range ballistic missiles.
Chinese Ambassador Liu Jieyi stressed the importance of reducing tensions on the Korean peninsula, telling reporters that this must be done "in a negotiated way."
"The most important thing of course is to reduce tension and also to get on the track of dialogue to seek progress in denuclearization and also commitment to peace and security on the Korean peninsula," Liu told reporters.
Japan's ambassador Koro Bessho said the council should consider further action to build pressure on Pyongyang.
"We have maintained our calm and self-restraint through all of this but we feel that enough is enough," said Bessho.
Since the launches, US President Donald Trump has reiterated Washington's "iron-clad commitment" to Japanese and South Korean security and threatened "very dire consequences" for Pyongyang.
France said it was discussing plans to impose new measures on North Korea within the European Union in a bid to close loopholes in UN sanctions resolutions.