The United States and South Korea completed the first round of talks on reviewing a bilateral trade deal on Friday, with Washington saying there was "much work to do" to reach a new agreement.

Since taking office in 2017, President Donald Trump has pulled the United States out of talks on a 14-nation Asia-Pacific trade pact, started negotiations on a new deal for the North American Free Trade Agreement between the U.S., Mexico and Canada, and initiated a review of the 2012 deal with South Korea.

Washington has taken a hard line in the NAFTA talks, which appear stalled with just two rounds of negotiations left, saying that concessions are the only way for Canada and Mexico to keep the deal.