Mustafa Sanalla, chairman of the National Oil Corporation, said that teams have begun assessing damage to the facilities in Zueitina, Ras Lanuf and al-Sidra, and plan to carry out immediate repairs if needed.
Forces loyal to General Khalifa Hifter, who is allied with the internationally recognized parliament, seized the terminals last Sunday.
The parliament does not recognize the recently formed, UN-backed government, in part because of differences over Hifter's future role.
The militia that previously controlled the facilities is allied with the UN-backed government, which is based in the capital, Tripoli.
The United States and other Western nations have called on Hifter's forces to withdraw from the terminals, saying the UN-backed Tripoli government is the "sole steward" of Libya's natural resources.
The parliament backed the seizure of the terminals, with Speaker Agila Saleh saying Hifter's forces "liberated" the terminals from "occupiers" who had hindered exports.
The oil-rich North African country slid into chaos after the 2011 uprising that toppled and killed Moammar Gadhafi, and is split between rival authorities based in the east and west.
The conflict has crippled Libya's once vibrant oil sector, denying it an estimated 100 billion US dollars in revenues over the past three years.
Libya exported 146 million barrels of oil in 2015, down from 531 million three years earlier, according to official figures.
Sanalla said the three terminals could handle up to 600,000 barrels per day within four weeks and 900,000 by the end of the year.
S/SH 11