North Korea test-fired Thursday what appeared to be surface-to-ship cruise missiles that traveled about 200 kilometers off its east coast, South Korea's military said.
These demands include the removal of almost 30,000 United States troops in South Korea meant to check North Korean aggression.
South Korean and USA officials had earlier said they aimed to deploy the system this year.
Compared to the different types of ballistic missiles Pyongyang has recently tested, the missiles launched on Thursday are considered to be more defensive in nature, created to defend against threats such as enemy warships.
Experts fear the tests indicate progress towards Pyongyang's ultimate goal of putting a nuclear warhead on a missile.
The test-launches were immediately reported to South Korean President Moon Jae-in right after being detected, according to local media reports.
The missiles were launched Thursday morning.
So far this year, Kim Jong Un has overseen the launch of 12 missiles, compared to the 16 that his father fired during his 17 years in power.
There have been nine ballistic missile launches by North Korea so far this year, the most recent of which fell into the EEZ surrounding Japanese waters on May 29.
The North's projectiles were fired into waters between South Korea and Japan where US aircraft carriers USS Carl Vinson and USS Ronald Reagan participated in joint exercises with the South Korean navy that ended earlier this week.
Moon is also concerned about economic retaliation from China, which staunchly opposes THAAD, seeing it as a threat to its military capabilities.
It is the first since the United Nations Security Council last week unanimously passed new sanctions against the North.
Gen. Vincent Brooks, who commands USFK, defended the system in a speech at a security forum last month, saying its deployment provides an unprecedented area defense against missiles from the North.
The short-range missiles do not pose a direct threat to the United States, according to the report. His decision to suspend the installation could strain relations with the White House, which has taken a hard line in confronting North Korea and its nuclear weapons program.
China's top priority is stability on its borders and, angry as it is about North Korea's continued provocations, it is considered unlikely to inflict serious pain on the Kim regime while it conducts only missile tests.