President Yoon Suk-yeol held an emergency meeting and instructed officials to quickly dispatch the disaster medical assistance team, the presidential office said at around 1 a.m. on Sunday as dozens of people are reported to be in cardiac arrest in Itaewon, central Seoul, where large crowds were celebrating the first outdoor no-mask Halloween since the pandemic.

"The top priority right now is saving and evacuating patients, and providing prompt transportation and treatment to victims (heading to) medical institutions," President Yoon said, according to the presidential office. He ordered officials to secure an ambulance route and immediately implement necessary measures, such as traffic control.

Yoon also ordered officials to restrict all vehicles and personnel from entering the area except for the purpose of transporting and treating patients.

The president told the Health Minister to quickly dispatch the disaster medical assistance team and secure emergency beds at nearby hospitals. He also instructed all relevant ministries and institutions, led by Interior Minister Lee Sang-min, to promptly provide first aid and treatment to victims.

Dozens of people fell into cardiac arrest near the Hamilton Hotel in Itaewon, central Seoul, on Saturday evening. Authorities said 146 people were killed and 150 injured in Halloween stampede in Seoul's Itaewon district as of 4:00 a.m. on Sunday.

Hours after the deadly incident, White House national security adviser Jake Sullivan tweeted that the US government is ready to provide South Korea with “any support it needs.”

“The reports out of Seoul are heartbreaking. We are thinking about all those who lost loved ones and hoping for a quick recovery for those injured,” Sullivan wrote.