Seoul, South Korea (CNN) -- Joint military exercises between South Korea and the United States officially ended Tuesday, the South Korean Defense Ministry said.
But the ministry noted that South Korea is still closely monitoring for possible provocation and possible missile launches by North Korea.
A torrent of unnerving threats from Pyongyang in recent weeks has strained already fragile relations in the region.
The North's rhetoric intensified when the U.N. Security Council voted last month to slap the tougher sanctions on the regime and amid the U.S.-South Korean military drills.
The tensions prompted the closure of Kaesong Industrial Complex in North Korea -- one of the few symbols of inter-Korean cooperation.
The complex, which sits just north of the Demilitarized Zone that separates the two countries, houses the operations of more than 120 South Korean companies.
During a frenzy of rhetoric aimed at South Korea and the United States earlier this month, the North began blocking South Koreans from entering the complex across the heavily fortified border.
It then pulled out the more than 50,000 North Koreans who work in the zone's factories, saying it was temporarily suspending activity there. The move surprised some observers since Kaesong was considered to be a key source of hard currency for the Kim Jong Un regime.
On Saturday, South Korea started withdrawing its remaining citizens from the manufacturing zone jointly operated with the North.
On Tuesday, the South's Unification Ministry said seven South Koreans remain at Kaesong to tie up loose ends.
This is not the first time Kaesong has shut down.
In 2009, North Korea temporarily suspended in Kaesong Industrial Complex several times, not permitting South Koreans to enter and exit the zone. The suspension also took place during the annual U.S.-South Korean joint military drill.
But if all South Korean workers pull out, it will be the first time the joint economic zone will have no South Korean workers since the business kicked off about a decade ago.
In 2012, the production value of the complex grew to $500 million; just five years earlier, it topped $100 million for the first time.
The average wage for North Korean workers in Kaesong Industrial Complex is $134 per month, according to the South Korean Unification Ministry. North Korean authorities take about 45% of their wages for various tax reasons.
CNN's Jethro Mullen contributed to this report.