China announced Monday it is banning imports of coal, iron ore, seafood and other products from North Korea in line with new United Nations sanctions approved earlier this month.

Chinese leaders had pledged to fully enforce the sanctions, which China and the other members of the U.N. Security Council unanimously adopted in response to North Korean ballistic missile tests.

The sanctions could block as much as $1 billion in North Korean exports.

China’s Commerce Ministry said the new trade ban will be fully in place by September 5.

U.S. President Donald Trump and other members of his administration have urged China to use its position as North Korea’s most important ally to pressure the country to give up its nuclear weapons program.

China has said it complies with U.N. resolutions, and on Monday the Chinese foreign ministry reiterated calls for restraint and the need to find a political resolution to the situation.