Monday's European Union talks were held amid mounting tensions over North Korea's nuclear program, following a string of missile tests in recent months that showed new capabilities.
The timing and scope of the USA action will depend heavily on how China responds to pressure for tougher steps against North Korea when US and Chinese officials meet for a high-level economic dialogue in Washington Wednesday, the administration sources told Reuters.
Kim Jong-un launched a sick celebration of the successful test launch of the country's first intercontinental ballistic missile.
Last year, China shipped to North Korea more than 96,000 tonnes of gasoline and almost 45,000 tonnes of diesel, worth a combined $64 million.
"We hope all relevant sides can make sure that they are clear that Security Council sanctions imposed on North Korea are not comprehensive economic sanctions".
"So far", Elise adds, "the North has not responded to the offer from Seoul".
"UN Security Council sanctions are not a total ban on shipments".
Chinese imports of North Korean coal in the first half fell 75 percent to 2.7 million tons from a year earlier following the suspension in February, according to Huang Songping, a Customs agency spokesman.
"It has nothing to do with creating income for DPRK nuclear programmes, so it is not on the sanctions list", Geng told a regular news briefing.
Trump has complained that trade increased between the two despite calling on his Chinese counterpart Xi Jinping to use the nation's unique diplomatic and economic clout over North Korea as leverage. Trump tweeted on July 5. The December 2015 talks at a now-stalled joint factory park in North Korea ended with no breakthroughs.
Previous Chinese customs data showed two-way trade with the North had risen 30.6 percent in dollar terms in the first three months of the year.
Kang Mi-jin, a defector who speaks regularly to market sources inside North Korea and reports commodity prices for Daily NK, said the price spikes in recent weeks were caused initially by the rumours - later confirmed - that China was restricting the flow of oil to North Korea.
She told the Security Council last week that the USA planned a new resolution that would also ensure existing measures are enforced.
"We will discuss with ministers what more we can do to facilitate a solution that, in our view, cannot be but a diplomatic and political one, " Ms. Mogherini said ahead of Monday's discussions.
But analysts say North Korea may accept the defense talks because it wants the South Korean Army to halt loudspeaker broadcasts at the border that began after North Korea's fourth nuclear test in January 2016.