March 24, 2017 0156 GMT
The drones, Gray Eagle Unmanned Aerial Systems (UAS) coming to South Korea are part of a broader plan to deploy a company of the attack drones with every division in the US Army, the spokesman said, Reuters reported on Tuesday.
"The UAS adds significant intelligence, surveillance and reconnaissance capability to US Forces Korea and our ROK partners," United States Forces Korea spokesman Christopher Bush said in a statement.
He did not say exactly when the drones would arrive in South Korea, officially the Republic of Korea (ROK).
North Korea has conducted two nuclear tests and a string of missile tests since the beginning of last year, despite the imposition of new UN sanctions.
North Korea fired at least four missiles toward Japan last week, three of which splashed down in waters near Japan, saying they were tests for a possible strike on US bases in Japan.
Last week, the US Ambassador to the United Nations, Nikki Haley, said Washington was reevaluating its North Korea strategy and "all options are on the table."
The sensor-rich MQ-1C Gray Eagle is a remotely controlled attack drone made by US-based General Atomics. They will be stationed at Kunsan Air Base, 180 km (112 miles) south of Seoul, Bush said, and would be permanently based in South Korea.
The aircraft is capable of carrying Stinger and Hellfire missiles, as well as other armaments.
It typically takes a company of 128 soldiers to maintain the drones, and there are usually 12 Gray Eagles per company.
On March 7, the United States deployed the "first elements" of the controversial Terminal High Altitude Area Defense (THAAD) anti-missile system to South Korea, despite angry opposition from China.
Once fully deployed in South Korea, a THAAD battery could theoretically use its radar to see and monitor activity beyond North Korea, deep into Chinese territory. Russia also worries the deployment could compromise its security, and said it would lead to a stalemate on the Korean peninsula.
The United States has about 50,000 troops in Japan, and another 28,000 in South Korea.
South Korea will hold a presidential election by May 9 after the impeachment and dismissal last week of its former president, Park Geun-hye, and policy on North Korea and the THAAD system are likely to be contentious issues in the campaign.