United States President Donald Trump signed a memo on Wednesday (Aug 12) that the White House said was aimed at empowering federal law enforcement to use cyber tools against transnational criminal organisations that operate in foreign jurisdictions to attack Americans.

Trump signed the national security presidential memorandum directing his administration to "leverage the capability and innovation of the private sector to help conduct these cyber operations under the direction, control, and authority of the US Government", the White House said.

The White House, in a fact sheet about the memo, cited ransomware attacks, financial frauds and other crimes run by foreign-based criminal organisations, referred to in the memo as "transnational criminal organisations".

The memo creates a framework that encourages private sector companies to enter into agreements with other private entities, as well as federal, state, local, tribal, and territorial agencies to gather threat information on transnational criminal organisations and propose cyber operations to address those threats, the White House added.

The memo directs the Department of Homeland Security, through the Homeland Security Task Force's National Coordination Center, to create a program "to conduct specific cyber operations that disrupt foreign TCOs" that will be overseen by DHS and the Department of Justice.

Under the supervision of the federal government, participating companies, once vetted, will conduct "cyber surveillance operations" and "cyber effects operations" against specified targets, according to the memo.

"Cyber effects includes the potential manipulation, disruption, denial, degradation, or destruction of information systems, networks, physical or virtual infrastructure controlled by information systems, or information resident thereon," according to the memo.

Participating companies will have to maintain a bond or escrow of at least US$1 million, according to the memo.

The idea of private sector firms participating in cyber operations against criminal and other targets is not new, and has been controversial in the past, for fears of escalation, inadvertent consequences, and inter-agency coordination issues.

DHS and the White House did not immediately respond to requests for additional details about the program.