The U.S. Department of Justice has sued to block Hewlett Packard Enterprise's $14 billion deal to acquire networking gear maker Juniper Networks, arguing that it would stifle competition, according to a complaint filed on Thursday.

Hewlett Packard is set to merge with Juniper for $14 billion. However, the U.S. Justice Department is suing to block the merger.

The Justice Department on Thursday sued to block the tie-up, a $14 billion deal that would join the second- and third-largest companies providing wireless networking solutions for large corporate customers.