At a plenary session, lawmakers passed a related motion in a 139-33 vote, with 22 abstaining.
Under the one-year contract signed in March, Seoul will pay 1.04 trillion won ($915 million) in 2019 for the operation of the 28,500-strong U.S. Forces Korea, up from 960 billion won the previous year.
|The National Assembly passes a motion to ratify South Korea`s defense cost deal with the United States and key bills on April 5, 2019. (Yonhap)|
The Special Measures Agreement is subject to parliamentary ratification in South Korea. But the U.S. does not require its congressional approval.
Since 1991, the USFK has used South Korean taxpayers' money to fund the wages for South Korean workers, the construction of base facilities and logistics.
The deal is the result of a series of tough negotiations between the allies.
The United States reportedly demanded a sharp hike of Seoul's share up to $1.2 billon. Washington also called for a one-year contract, while Seoul wanted it to last three to five years.
President Donald Trump has openly pressed some U.S. allies to stop what he calls a free ride in their national defense.
The National Assembly, meanwhile, passed 110 bills on the final day of the extraordinary session.
The legislation includes a revised bill aimed at strengthening punishment against those who assault hospital employees.
The so-called Lim Se-won law was enacted amid mounting calls to guarantee the safety of medical workers following the murder of a psychiatrist by his patient in December.
A man suffering from bipolar disorder stabbed his doctor, Lim, to death during treatment at a general hospital in Seoul.
Under the bill, assailants can face life imprisonment or jail terms of at least five years if medical workers are killed in attacks while on duty.
In the case of injury, attackers could face prison terms of up to seven years and more than 10 million won in fines.
Rival parties failed to handle two contentious labor bills on the flexible work time system and the minimum wage scheme during the March session.
They agreed to open an April extra session Monday for one month to handle key bills on the economy and reforms. (Yonhap)