China concerned by U.S. probe of aluminum imports on national security grounds

China is "concerned" by Washington's probe into aluminum imports from the world's top producer of the metal on national security grounds, China's Commerce Ministry said on Thursday, as the two economies' 100-day trade talks continue.

Washington is investigating aluminum imports from China under the rarely used section 232 of the Trade Expansion Act of 1962 that allows restrictions on imports for reasons of national security. The administration is also conducting a separate investigation into steel.

"The scale of 'national security' is very wide and lacking clear definition, which is easily misused and therefore posing restrictions on normal flow of international trade," Sun Jiwen, spokesman at China's Commerce Ministry, said at a weekly briefing.

His comments come after senior officials told Reuters that U.S. President Donald Trump is growing increasingly frustrated with China over its inaction on North Korea and bilateral trade issues and is now considering possible trade actions against Beijing.

"It is inevitable to have some friction as the bilateral trade between China and U.S. is massive," Sun said.

"Generally the cooperation between China and the U.S. goes smoothly and has achieved many positive results. China will continue making effort on it, and hope the U.S. can also work toward the same direction," said Sun.

In April, Beijing and Washington agreed to a 100-day plan for trade talks in a bid to boost access to each other's markets.

So far, the United States has accepted imports of cooked poultry from China and in turn, China has agreed to drop a 14-year ban on beef imports.