US President Donald Trump said the move was nothing compared to what would have to happen to deal with North Korea.
The UN sanctions are an attempt to starve the country of fuel and income for its weapons programmes.
The measures restrict oil imports and ban textile exports, and were approved after North Korea's sixth and largest nuclear test earlier this month.
Han Tae Song, North Korea's ambassador to the UN, said he "categorically rejected" what he called an "illegal resolution".
"The forthcoming measures by DPRK [the Democratic Republic of Korea] will make the US suffer the greatest pain it has ever experienced in its history," he told a UN conference in Geneva.
"Instead of making [the] right choice with rational analysis... the Washington regime finally opted for political, economic and military confrontation, obsessed with the wild dream of reversing the DPRK's development of nuclear force - which has already reached the completion phase."
- BBC -