South Korea and North Korea have agreed to hold de-escalation talks Saturday as the two countries prepare for a possible military clash. Over 3,500 South Koreans have been evacuated near the border with the North as tensions mount between the two rivals.

Officials from the two countries are scheduled to meet for the first high-level talks in nearly a year at the “truce village” of Panmunjom, inside the Demilitarized Zone (DMZ). South Korea's national security adviser Kim Kwan-jin and Unification Minister Hong Yong-pyo will meet North Korea's top political officer Hwang Pyong So -- also considered the second most important official after supreme leader Kim Jong Un -- and Kim Yang Gon, secretary of the central committee of the Workers' Party of Korea, the Associated Press reported, citing South Korea's presidential office.

Meanwhile, fighter jets from the United States and South Korea swept through the sky in a show of force against the North's threats. Four F-16 fighter jets from the U.S. Forces Korea and four South Korean F-15K jets joined the combat drill Saturday, an official from South Korea's Joint Chiefs of Staff said, according to Yonhap news

"It was a flight aimed to show off the military might of South Korea and U.S.' combined air force power," the official reportedly said.

Pyongyang has threatened “strong military action” if Seoul does not dismantle loudspeakers broadcasting anti-North Korean propaganda across the border by Saturday. 

"If South Korea does not respond to our ultimatum... our military counteraction will be inevitable and that counteraction will be very strong," North Korea's U.N. Ambassador An Myong Hun reportedly said Friday. However, South Korea rejected the ultimatum to halt anti-Pyongyang broadcasts.

Tensions between the two countries escalated after South Korea fired dozens of artillery rounds across the border, saying North Korea had fired first in an apparent protest to loudspeaker broadcasts. South Korea, which raised its military readiness to its highest level, reportedly warned North Korea Friday to refrain from engaging in "rash acts" or face strong punishment.