Joe Biden and South Korean president Yoon Suk Yeol held a news conference at the White House on Wednesday, 26 April.
The world leaders were set to sign an agreement that includes plans to have U.S. nuclear-armed submarines dock in South Korea for the first time in more than 40 years.
It aims to be a show of support to Seoul amid a period of heightened anxiety for both leaders over an increased pace of ballistic missile tests by North Korea over the last few months.
Earlier on Wednesday, Mr Biden said of his counterpart: "Mr. President, ours is a future filled with unimaginable opportunity and endless possibility. Nothing — nothing — is beyond our ability to reach when our nations and our people stand united. We have proven that time and again over the last 70 years."
Yoon opened his state visit to Washington on Tuesday by touring a NASA facility with Vice President Kamala Harris.
“Our alliance is leading on some of the most important and pressing issues of our time,” Harris said in remarks at the NASA facility.
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