China's Ministry of Commerce said in a statement on its website on Saturday that China would limit exports of refined petroleum products from October 1, and ban condensates and liquefied natural gas immediately.
China will also ban textile imports from the North Korea, the ministry said.
Textiles are one of North Korea's last major sources of foreign revenue following repeated rounds of UN sanctions under which Beijing cut off purchases of coal, iron ore, seafood and other goods.
China accounts for about 90 percent of North Korea's trade, making its cooperation critical to any efforts to derail Pyongyang's development of nuclear weapons and long-range missiles.
'Too soon to tell'
Al Jazeera's Adrian Brown, reporting from Beijing, said that "it is too early to say how effective these new limits will be".
He added: "Of course, it's going to take months for the impact of these sanctions to be felt, but certainly banning imports of North Korea textiles will hurt the regime because textiles provide what the regime really needs most right now, which is hard currency."
Chinese leaders were long North Korea's diplomatic protectors but express increasing frustration with the government of Kim Jong-un.
They supported the latest rounds of UN Security Council sanctions but are reluctant to push Pyongyang too hard for fear the government might collapse.
They also argue against doing anything that might hurt ordinary North Koreans.
Joseph Cheng of the Chinese University of Hong Kong told Al Jazeera that "China wants to demonstrate its support of the world community's position dissuade North Korea from continuing to hold nuclear tests and long-range missile tests".
But Cheng also said that Beijing understands that economic sanctions alone "will not be able to persuade Pyongyang to give up their programmes".
His comments came a day after he signed an executive order allowing Washington to ramp up sanctions against North Korea over its nuclear missile programme.
Trump said the measure would allow sanctions against "individuals and companies that finance and facilitate trade" with Pyongyang.
Also on Friday, North Korean Foreign Minister Ri Yong-ho said his country could consider a hydrogen bomb test on an unprecedented scale on the Pacific Ocean - a threat, Japan labelled as "totally unacceptable".
Source: Al Jazeera and news agencies