Seoul and Washington have held 10 rounds of talks since March, amid Trump's calls for South Korea to pay more.
The deal will officially go into effect after it receives parliamentary approval in South Korea, which is expected to take place in April, according to Yonhap news agency.
About 28,500 USA troops are stationed in South Korea, where the United States has maintained a military presence since the 1950-53 Korean War.
The U.S. State Department senior adviser for security negotiations and agreements, Timothy Betts, met Kang before signing the agreement on behalf of the United States, and told her the money represented a small but important part of South Korea's support for the alliance.
At their first meeting in Singapore previous year, the notoriously unpredictable US president had made a shock decision to suspend US-South Korea military drills.
"The two countries reaffirmed. the importance of a strong South Korea-US alliance and the need for a stable stationing of the US troops", it said in a statement issued after a signing ceremony.
The Stanford experts said it was their assessment that "North Korea can not deliver a nuclear warhead with any measure of confidence to the USA mainland", although Hecker said its nuclear weapons were a real threat to Japan and South Korea.More news: Speaker Pelosi admonishes freshman Omar over Israel tweet
More news: Kylie Jenner throws extravagant party for Stormi's first birthday
More news: Will Smith's Genie Revealed In New 'Aladdin' Trailer
Seoul said Sunday it agreed to hike its payment for maintaining American troops on its soil, settling a dispute with its longtime ally ahead of a second summit between the U.S. and North Korea.
The production came in spite of nuclear talks with the USA led by the historic summit in Singapore last June.
The South Korean Parliament has to approve the agreement before it becomes final. -North Korea summit, Seoul officials said.
In order for Pyongyang to have any chance at hosting, North Korea will have to show a willingness to break down their nuclear program, in which President Donald Trump's summit in Hanoi at the end of the month with Kim Jong-Un will be vital.
About 70 percent of South Korea's payment funds the salaries of some 8,700 South Korean workers who provide administrative, technical, and other services for the USA military. There are about 28,500 USA troops stationed in South Korea.
U.S. Special Representative for North Korea Stephen Biegun held three days of talks in Pyongyang last week to prepare for a second Trump-Kim summit due to be held in Hanoi on February 27 and 28. Most U.S. troops were withdrawn in 1949 but they returned the next year to fight alongside South Korea in the 1950-53 Korean War. After the meeting, Trump suspended major joint military exercises with South Korea.