Japan's Nippon Steel said on Thursday it has extended the closing period for its $15 billion purchase of U.S. Steel, expressing confidence that the acquisition will protect and grow the American company.

A committee of top government agency officials has notified President Joe Biden that it has not reached a consensus on whether a sale of US Steel to a Japanese rival poses a national security risk, according to two sources familiar with the matter.

Japan's Nippon Steel said on Thursday that it had extended the closing period for its planned purchase of U.S. Steel, worth nearly $15 billion.