Vice President Mike Pence made a surprise visit Monday to the Korean Demilitarized Zone that separates communist North Korea from democratic South Korea, and he put North Korea on notice.

According to reports, Pence, speaking from inside the DMZ, warned the Kim Jong-Un regime that the “era of strategic patience” is over, referring to North Korea’s insistence on developing nuclear weapons and missiles capable of reaching the U.S.

"President [Donald] Trump has made it clear that the patience of the United States and our allies in this region has run out and we want to see change. We want to see North Korea abandon its reckless path of the development of nuclear weapons, and also its continual use and testing of ballistic missiles is unacceptable,” Pence said, according to Fox News.

While there, Pence also reiterated the "ironclad and immutable” relationship between the U.S. and South Korea, and Trump’s desire to achieve security in the region "through peaceable means, through negotiations."

"But all options are on the table as we continue to stand shoulder to shoulder with the people of South Korea for denuclearization of this peninsula and for the long-term prosperity and freedom of the people of South Korea,” Pence said.

Pence’s comments come as he begins a 10-day trip of the Asian Pacific, his first since taking office. They also came on the heels of another ballistic missile test by North Korea that failed over the weekend.

Last week, Trump ordered U.S. Carrier Strike Group 1, which includes the powerful aircraft carrier USS Carl Vinson, to the Western Pacific near waters off the Korean Peninsula in response to heated rhetoric and aggression from North Korea.