Gen. Keith Alexander said the data, allegedly based on the NSA's collection of tens of millions of phone calls in France and Spain and mentioned in documents leaked by former NSA contractor Edward Snowden, were actually handed over to the United States by European intelligence agencies.
The NSA has come under criticism after reports suggested it monitored the telephones and emails of leaders of countries allied with the United States, notably German Chancellor Angela Merkel.
Alexander told the House Intelligence Committee reports of bulk collection of European phone data by the NSA were "totally false."
"This was not information we collected on European citizens," he said. "It represents information that we and our NATO allies have collected in defense of our countries and in support of military operations."
A bipartisan bill was introduced in Congress Tuesday to prevent NSA eavesdropping on Americans' telephone calls and would heighten oversight of the agency, The Financial Times reported.
Prior to the hearing, Senate Select Committee Chairwoman Diane Feinstein, D-Calif., promised a total review of all U.S. surveillance programs, and said she expected the Obama administration would end all spying on foreign allied leaders.
"It is abundantly clear that a total review of all intelligence programs is necessary so that members of the Senate Intelligence Committee are fully informed as to what is actually being carried out by the intelligence community," said Feinstein, an Obama ally and usually one of the NSA's strongest Capitol Hill defenders.
"Unless the United States is engaged in hostilities against a country or there is an emergency need for this type of surveillance, I do not believe the United States should be collecting phone calls or emails of friendly presidents and prime ministers," Feinstein said in a statement.