The collection of information from SMS text messages by the spy agency is called Dishfire.
The database is used to extract information from people, including location, contact networks, and credit card details, the Guardian reported on Thursday based on material provided by American whistleblower Edward Snowden.
The NSA called SMS text messages a “goldmine to exploit” in a 2011 top-secret document.
The Dishfire program collected an average of 194 million text messages a day in April of 2011.
Another document referred to content about messages combined with automatic alerts for international network roaming or missed calls as “analytic gems.”
After collecting texts, an NSA program called Prefer conducted automatic analyses of the millions of messages to dig up details about people’s travel plans, financial transactions and other data.
The UK spy agency, Government Communications Headquarters (GCHQ), also used the NSA database to search the metadata of “untargeted and unwarranted” communications belonging to people in Britain, according to the documents.
Meanwhile, a spokeswoman for the NSA said in a statement that any implication that the agency’s collection was “arbitrary and unconstrained is false.”
The agency’s capabilities were directed only against “valid foreign intelligence targets” and were subject to stringent legal safeguards, she said.
The latest revelation will intensify global pressure on US President Barack Obama.
President Obama is set to propose a series of changes to the NSA’s spying programs in a speech at the Justice Department on Friday.