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 . Key dates in U.S. military moves near North Korea . 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 . Training to go supersonic with South Korea 's Top Guns . Seven remain . 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 . Threats of annihilation normal for South Koreans . 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 . South Korea pulls out citizens from joint industrial zone . CNN 's Jethro Mullen contributed to this report .
The military would end after a rash of fiery rhetoric from North Korea . The regional crisis prompted the closure of the Kaesong Industrial Complex . The complex is located in the North but serves South Korean industries . 7 South Koreans remain at the inter - Korean complex .