He made the remarks in an exclusive Yonhap News Agency article published on Friday, where the former Vice President also said that he would keep pressing toward North Korea's denuclearization through "principled diplomacy".
"As President, I'll stand with South Korea, strengthening our alliance to safeguard peace in East Asia and beyond, rather than extorting Seoul with reckless threats to remove our troops," Biden said in the article, titled "Hope for Our Better Future".
"I'll engage in principled diplomacy and keep pressing toward a denuclearized North Korea and a unified Korean Peninsula, while working to reunite Korean Americans separated from loved ones in North Korea for decades," he added.
In the article, which comes just five days ahead of the much-anticipated US presidential election, Biden recalled his 2013 trip to the Demilitarized Zone (DMZ) on the inter-Korean border.
"I will never forget standing less than 100 feet away from North Korea at the DMZ with my granddaughter, Finnegan, beside me.
"I felt the pain of division on the Korean Peninsula and the separation of families since the Korean War," the former Vice President said in the Yonhap News Agency artcile.
Biden also promised efforts to help all immigrants, including undocumented Koreans.
"I'll work to fix our broken immigration system, provide a roadmap to citizenship for undocumented Koreans, and recognize the tens of thousands of Korean adoptees as the Americans they are.
"I'll fight for a better future for all our children and grandchildren. 'Katchi Kapshida'," he said.
'Katchi Kapshida' is the catch phrase of the Korea-US alliance, which means "we go together".