The US today said Pakistan is working hard to ensure that its strategic export controls are in line with international standards, days after it sanctioned seven Pakistani companies suspected of having links to nuclear trade.

Recently, the US added seven Pakistani firms to a list of foreign entities that pose a "significant risk" to its national security and interests by allegedly engaging in nuclear trade, denting Islamabad's bid to join the elite Nuclear Suppliers Group (NSG).

The move would also have a negative impact on Pakistan's determined bid to join a Vienna-based 48-member group which controls the global nuclear trade.

"We recognise that Pakistan is engaged with the international community on nuclear safety and security issues, and is working hard to ensure its strategic export controls are in line with international standards," a State Department spokesperson told.

The spokesperson was responding to a question on the recent determination of US Department of Commerce to that seven entities from Pakistan are "acting contrary to the national security or foreign policy interests of the United States".

One company from Singapore and 15 others from South Sudan were also added to the list published in the Federal Register on March 22.

"We regularly add entities to the Entity List based on US national security and foreign policy interests. It is not country-specific," the State Department Spokesperson added.

The US said this, days after it sanctioned seven Pakistani companies suspected of having links to nuclear trade.