A U.S. investigation into whether uranium imports are harming national security will have “no immediate effect” on existing contracts or deliveries of Saskatchewan-based Cameco Corp. (CCO.TO), the company said in a release on Wednesday.

U.S. uranium producers Energy Fuels Inc. and Ur-Energy Inc. filed a petition in January asking the Commerce Department to investigate the matter under Section 232 of the 1962 Trade Expansion Act, the same provision U.S. President Donald Trump used to slap tariffs on steel and aluminum imports. U.S. industry wants the government to shield it from competition from state-owned companies in countries including Russia, Canada and Kazakhstan.

“If the issue in question is the overreliance of the United States on uranium supplied by state-controlled enterprises from countries not aligned with American policy interests, this clearly does not apply to Canada or Cameco,” the company’s CEO Tim Gitzel said in the release.

The U.S. is currently Cameco’s largest customer by country. About 30 per cent of the company’s total sales by volume last year were to U.S.-based utilities, the company said.

U.S. uranium producers want about 25 per cent of the domestic market to be reserved for American miners, which produced about 1.2 million pounds last year, the lowest in at least 25 years.

Cameco operates mines in Wyoming and Nebraska which are currently in a state of care and maintenance. When the mines were operational, Cameco was the largest uranium producer in the U.S.

It’s too early to speculate on what impact the investigation will have on Cameco’s operations, said Gitzel.

“We will need to see what the investigation finds, if any trade action is recommended, and what specific remedies might be pursued before the potential impact, positive or negative, can be determined,” he said in the release.