A South Korean government source told Yonhap the supercarrier is on an open-ended mission.
"Joint drills between South Korea and the United States [involving the Vinson] are under way," said a spokesman for the South Korean navy.
A closing date has not been determined, he said.
The Carl Vinson and its strike group were deployed to the peninsula after U.S. President Donald Trump said all options were on the table, including military intervention, in response to North Korea's unabated nuclear weapons and ballistic missile development.
Japanese newspaper Yomiuri Shimbun reported aircraft carrier USS Ronald Reagan left Yokosuka port on Tuesday, and may have been deployed to guard against North Korea provocations.
The 5,000 sailors on the ship departed a day later than scheduled because of a maintenance issue, Stars and Stripes reported.
The continued deployment of aircraft carriers to warn North Korea comes at a time of political transition in South Korea.
Newly elected South Korean President Moon Jae-in has said he would stand up to North Korea provocations, but has also promised his supporters a more conciliatory approach to Pyongyang that could ease further tensions.
On Tuesday in Seoul, Moon met with Trump adviser Matt Pottinger, who serves as senior director for East Asia at the National Security Council.
The two sides met for an impromptu 7-minute conversation during Pottinger's visit to Seoul, following the U.S. official's trip to Beijing for China's Belt and Road Forum, according to News 1.
Moon said he is dispatching a special envoy to Washington to reaffirm the U.S.-Korea alliance. The South Korean leader added he "hopes to meet soon with President Trump," according to the report.
Pottinger spoke separately with reporters after meeting with South Korea's deputy foreign minister to arrange a summit, Newsis reported.
The U.S. adviser said a dialogue between the United States and North Korea would only be feasible when the right conditions are established, according to the report.