However, a joint statement issued after the summit said the two sides "further committed to foster a truly fair and level playing field" without mentioning the renegotiation of the trade deal.

On Saturday, Moon told South Korean correspondents in Washington that any talk of the renegotiation of the free trade deal is "outside of the agreement" he reached in summit talks with Trump.

South Korea will closely look into the matter and take measures, a trade ministry official here said, noting Trump's intention over the free trade deal is not clear.

During and after the talks with Moon, Trump vowed to seek a new trade pact with South Korea, blaming the current deal for enlarging American deficits.

Trump said the trade deal has been rough for the US, noting that the US trade deficit with South Korea has increased by more than $11 billion between 2011, a year before the free trade deal went into effect, and last year.

Lee Dong-bok, a senior official at the Korea International Trade Association, said Seoul and Washington could find common ground in partly amending the free trade deal in case the two sides renegotiate. He also said the US appears likely to address an imbalance in bilateral auto and steel trade.

The association said an imbalance in bilateral trade stems from differences in economic and industrial structures between South Korea and the US, not from the free trade deal.

The association noted manufacturing is the mainstay of South Korea's economy, and the growing US demand for imports amid its economic recovery is to blame for the trade gap. (Yonhap)