Park defeated her liberal rival Moon Jae-in in Wednesday's presidential election with pledges to revive the nation's sluggish economy and seek more engagement with North Korea than the incumbent President Lee Myung-bak.
"I have just made my first call on the president-elect and very much look forward to working closely with her administration to further enhance our close, constructive and deep cooperation with the Republic of Korea," U.S. Ambassador Sung Kim said in an article posted on the embassy's Web site.
"The alliance between our strong democracies is strong and deep," Kim said. "As I look forward to what we can accomplish together next, I believe our goals for the future are only limited by our imagination."
In a congratulatory message to Park, U.S. President Barack Obama said the bilateral alliance "serves as a lynchpin of peace and security in the Asia Pacific, and our two nations share a global partnership with deep economic, security and people-to-people ties."
North Korea launched a long-range rocket that put a satellite into orbit last week, a move condemned by the U.N. Security Council as a banned test of ballistic missile technology.
Currently, South Korea and the U.S. are asking the Security Council to take a tougher measure against the North's rocket launch.