Iran is rebuilding its armed forces and weapons production faster than Washington expected, CNN reported, citing sources familiar with U.S. intelligence assessments.

According to the channel, U.S. officials initially believed Tehran would need more time to restore its military capabilities. But during the six-week ceasefire that began in April, Iran had already restarted some facilities producing drones.

Several U.S. intelligence agencies now estimate that Iran could fully restore its capacity to carry out UAV strikes within six months.

Mohammad-Bagher Ghalibaf, speaker of the Iranian parliament, had earlier said the country’s armed forces used the pause in fighting as much as possible to regain lost capabilities.

The United States and Israel began strikes on Iranian territory on February 28. More than 3,000 people were killed as a result of the aggression. In April, Washington and Tehran announced a ceasefire. Later talks in Islamabad ended without any breakthrough. There have been no reports of renewed fighting since then, though the United States has begun blocking Iranian ports.