The US military is to establish a special unit to develop cyber-weapons to defend military networks.
The unit will also help safeguard civilian systems, Pentagon press secretary Geoff Morrel said.
The UK government has announced similar plans. It aims to recruit white hat hackers to detect, repair and prevent cyber attacks. It plans a UK Cyber Security Operations Centre to collate, assess and distribute threat information and carry out counterattacks
The US unit will be set up as part of the US Strategic Command, which is responsible for commanding operations in nuclear and computer warfare.
The UK unit is be set up in September. The US military cyber command is to be launched a month later and is expected to be fully operational by October 2010.
Both countries have expressed concerns about overseas hackers stealing sensitive data from government departments and businesses.
Earlier this month, US president Barack Obama acknowledged that the cyber threat is one of the most serious economic and national security challenges faced by the US.
Top of Obama's action list is to appoint a single cyber security tzar to lead an office in the White House to co-ordinate all cybersecurity-related government policy.
US commentators said the authority of the White House will help overcome the turf battles that have hampered co-ordination of cyber defences in the past.
Many security industry representatives are in favour of the UK doing the same by appointing a centrally accountable official who reports to the prime minister.