March 17 (Reuters) - OpenAI has signed a new deal to

sell access to its AI models to U.S. defense and government

agencies through Amazon's ( AMZN ) cloud unit for classified and

unclassified work, the ChatGPT maker said on Tuesday.

The contract enables OpenAI to support the Pentagon under a

deal it secured late last month, after the agency dropped its

previous AI provider, Anthropic.

Anthropic, which won a Pentagon contract worth up to $200

million in July 2025, had been a key U.S. defense AI supplier,

working with Palantir ( PLTR ) and Amazon Web Services (AWS) to

deploy its Claude models in classified military and intelligence

systems.

But its relationship with the Pentagon collapsed in February

after Anthropic refused to allow unrestricted military use of

its AI, particularly for domestic surveillance and autonomous

weapons. Following which, the Pentagon labeled it a "supply

chain risk" and effectively cut it off from government work.

OpenAI, which had previously focused on unclassified

government use, has now secured a Pentagon contract to provide

its models for classified operations.

Its partnership with AWS builds on this latest shift,

reflecting how access to government and defense contracts,

especially via cloud providers already embedded in federal

systems, is becoming a key battleground.

Securing government contracts could also help the ChatGPT

maker attract large corporate clients, which often see

high-stakes public sector work as a strong signal of trust and

reliability.

Following OpenAI's transition to a for-profit structure last

fall, the company updated its agreement with Microsoft ( MSFT )

to allow partnerships with rival cloud providers in selling AI

to national security customers, including the Pentagon.

(Reporting by Akash Sriram in Bengaluru; Editing by Anil

D'Silva and Shinjini Ganguli)