WASHINGTON —The Trump administration on Tuesday imposed sanctions on 10 companies and six individuals from mostly China and Russia who it says helped North Korea develop its nuclear and ballistic missile programs.

"We are taking actions consistent with U.N. sanctions to show that there are consequences for defying sanctions and providing support to North Korea, and to deter this activity in the future," said Treasury Secretary Steve Mnuchin in a statement.

The new sanctions are the latest in a raft of blacklists issued in recent months to punish Chinese and Russian companies that try to evade international efforts to isolate North Korea. They seek to cut violators off from the U.S. financial system, which extends to banks in Russia and China that use it to transfer money between institutions.

The sanctions come amid high tensions between the U.S. and North Korea. The North warned Sunday that it would launch a nuclear war if the annual U.S.-South Korea military exercises this week turn to “actual fighting.” Earlier in August, North Korean leader Kim Jong Un and President Trump traded warnings over a North Korean plan to test missiles that would land near the U.S. territory of Guam.

Trump has sought China’s assistance in reigning in North Korea’s nuclear program, which has demonstrated significant strides in the past year. But he later expressed frustration with North Korea's key ally China, saying the U.S. would use the tools at its disposal to increase pressure on the North.

Tuesday's sanctions targeted companies and individuals involved in North Korean weapons programs, its coal and oil trade, and its foreign worker program, which the State Department says are three major sources of funding for the North's illicit weapons programs.

North Korea's foreign coal trade provides more than $1 billion in revenue annually. The sanctions target six Chinese companies, two Singapore-based companies that sell oil to North Korea, a Russian company, four Russian nationals and a construction company based in Namibia:

• China-based Dandong Rich Earth Trading Co. for its support to previously sanctioned entities that act on behalf of North Korea's General Bureau of Atomic Energy, which is responsible for the North's nuclear program. Dadong purchased vanadium ore from North Korea in violation of United Nations sanctions resolutions, Treasury said.

• Moscow-based Gefest-M LLC and its Russian director, Ruben Kirakosyan, for helping procure metals for Korea Tangun Trading Corporation, another previously sanctioned entity involved in North Korea's missile and weapons programs, Treasury said.

• China- and Hong Kong-based Mingzheng International Trading Limited, which Treasury said acts as a front company for a previously-designated bank that has handled transactions in U.S. dollars for North Korea's primary foreign exchange bank for the North's proliferation network.

• Three Chinese coal companies responsible for importing nearly half a billion dollars’ worth of North Korean coal between 2013 and 2016. The companies — Dandong Zhicheng Metallic Materials Co., Ltd., JinHou International Holding Co., Ltd., and Dandong Tianfu Trade Co., Ltd. — helped North Korea generate funds that fuel its nuclear and ballistic missile programs, Treasury said.

• Three Russian individuals and two Singapore-based companies that helped provide oil to North Korea, by working with a previously sanctioned bank and individual, and attempting to send millions of dollars in payments on behalf of North Korean-related transactions.

• A North Korean subsidiary of Mansudae Overseas Projects Group of Companies, which was previously sanctioned by the U.N. for exporting workers from North Korea to generate revenue for the government, the Workers' Party of Korea and for the country's Munitions Industry Department, which is responsible for overseeing the North's ballistic missile program. The workers have been used to build statues abroad, Treasury said.

• A Namibia-based subsidiary of a Chinese company that took over four Namibian government construction projects on behalf of Mansudae, which was designated by U.N. sanctions.

More:North Korea warns of nuclear war if U.S. drill turns to 'actual fighting'

Related:North Korea's latest threat to South Korea, U.S.: 'Merciless retaliation'

Marine Corps:Gen. Joseph Dunford: War with North Korea ‘horrific’ but nukes ‘unimaginable’