The U.N. resolution also outlines measures to step up scrutiny of suspicious sea shipments and air cargo. And it expands restrictions to encompass several institutions and senior officials in the North's weapons industry, as well as a range of materials and technology known to be used in uranium enrichment.
It also blocks the sale of luxury goods -- such as yachts and certain high-end jewelry -- to North Korea.
"As a result, North Korea's ruling elite, who have been living large while impoverishing their people, will pay a price" for the ongoing nuclear activities, Rice said.
Some doubt whether the new measures will make much difference.
Sanctions imposed after previous nuclear tests and rocket launches have failed to deter Pyongyang.
China will go a long way toward determining whether the new sanctions really do have "bite," analysts say.
"As long as China allows North Korea to operate, as long as China provides food, energy assistance, and investment, the sanctions really don't matter," said Doug Bandow of the Cato Institute.
North Korea notoriously allows many of its people to live in malnutrition and starvation. Still, the country needs a functioning economy, partly to finance its military, Bandow explained.
"Kim Jong Un is now paying the price for going ahead with a nuclear test despite Chinese warnings not to create trouble during the political transition that has been under way in Beijing the past year," Mark Fitzpatrick, director of the Non-Proliferation and Disarmament Programme at the UK-based International Institute for Strategic Studies, said this week.
Future levels of Chinese grain sales to North Korea are a possible indicator of Beijing's commitment to putting meaningful pressure on Pyongyang, he said.
Ken Gause, an analyst with CNA, said the new sanctions won't deter North Korea from building up its nuclear program.
"North Korea last year inserted language into its constitution that the country is a nuclear power. To walk back from this, especially under pressure from the outside world, would undermine Kim Jong Un's legitimacy and make him vulnerable. He will not do this," said Gause.
North Korea casts U.N. sanctions as part of an aggressive, U.S.-led conspiracy against it.
North Korea said the underground nuclear blast it conducted February 12 was more powerful than its two previous detonations and used a smaller, lighter device, suggesting advances in its weapons program.
It was the first nuclear test the isolated state has carried out since Kim inherited power in December 2011 after the death of his father, Kim Jong Il, who made building up North Korea's military strength the focus of his 17-year rule.
The test followed the North's long-range rocket launch in December that succeeded in putting an object in orbit. Pyongyang insisted the launch had peaceful aims, but it was widely viewed as a test of its ballistic missile technology.
North and South Korea have technically been at war for decades. The 1950-53 civil war ended in a truce rather than a peace treaty.
China supported the North with materiel and troops in the Korean War. The United States backed the South in the conflict, with soldiers from the two countries fighting side by side. About 28,500 U.S. soldiers are currently stationed in South Korea.