Facebook said Tuesday it received more than 25,000 government data requests in the first half of 2013, with the largest number from the United States.

The company's first "transparency report" showed Facebook received between 11,000 and 12,000 requests for data in the United States, affecting between 20,000 and 21,000 users.

It also received more than 14,800 requests from 70 other countries for various government investigations.

Facebook said the report includes "both criminal and national security requests" but without a detailed breakdown.

"We have reported the numbers for all criminal and national security requests to the maximum extent permitted by law," a statement by the huge social network said.

"We continue to push the United States government to allow more transparency regarding these requests, including specific numbers and types of national security-related requests. We will publish updated information for the United States as soon as we obtain legal authorization to do so."

The report comes with US tech companies under pressure following revelations of a secret program which scoops up vast amounts of data from Internet firms.

Tech firms including Facebook have been seeking to release more information on government data requests, in the belief that this would reassure customers.

Facebook's report follows the release of similar information from other tech firms including Google, Microsoft and Twitter.

The Facebook report said at least some data was released in 79 percent of US data requests.

"Transparency and trust are core values at Facebook," the company's general counsel Colin Stretch said.

"We strive to embody them in all aspects of our services, including our approach to responding to government data requests. We want to make sure that the people who use our service understand the nature and extent of the requests we receive and the strict policies and processes we have in place to handle them."

The second largest number came from India, where 3,245 requests were made, affecting 4,144 users, Facebook said. The company provided at least some data in 50 percent of those cases.

Facebook said that in the United States, it requires "a valid subpoena," court order or search warrant in order to turn over data.

In other countries, Facebook said, "We disclose account records solely in accordance with our terms of service and applicable law."

Facebook said the third-largest number of requests came in Britain (1,975) followed by Germany (1,886), Italy (1,705) and France (1,547).

Google, in its most recent transparency report covering the last six months of 2012, said it received 21,389 government requests.

Kevin Bankston at the Center for Democracy and Technology, a digital rights group, commended Facebook for its action, saying that "sunlight is the best disinfectant, and basic numbers about the scope of surveillance of Facebook users can serve as an important early warning system for detecting abuse or overuse of a government's authority to demand user data."

But he added that it was "disappointing that Facebook is still prohibited by law from disclosing specific information about the number of foreign intelligence and national security-related data demands it receives from the US government."