Finance Minister Choi Sang-mok is briefed by a KEB Hana Bank official at the foreign exchange dealing room at the bank's headquarters in Seoul, Monday. (Yonhap)

South Korea’s won-dollar trading on the first day with extended trading hours has gotten off to a smooth start with ample liquidity and no significant increase in volatility, the country’s financial authorities said Tuesday.

Starting from Monday, Korea has extended won trading hours to make the currency more tradable and accessible to global investors. Dollar-won trading hours are changed to 9 a.m. to 2 a.m., compared to 9 a.m. to 3:30 p.m. earlier.

Choi Sang-mok, Korea's deputy prime minister and Minister of Economy and Finance and Bank of Korea Deputy Gov. Ryoo Sang-dai visited the foreign exchange dealing room of the KEB Hana Bank headquarters in Seoul on Monday night for an on-site inspection of the first day with longer trading hours.

The minister highlighted that the structural revamp of the forex market aimed at developing openness and competitiveness that meet the global standard.

"The government will continue to actively extend support to domestic banks to help them play a leading role in ensuring the stable implementation of these changes," he said.

Ryoo emphasized that the role of domestic financial institutions is important to “prevent the foreign exchange market from experiencing excessive volatility after structural improvement.”

“The foreign exchange authorities also plan to carefully monitor market trends and make efforts to ensure stability.”

The total spot trading volume of the first day of trading ended at 2 a.m. Tuesday stood at $12.57 billion, which included $2.46 billion traded between 3:30 p.m. on Monday and 2 a.m. on Tuesday, according to the finance ministry.

The average trading volume per hour between 9 a.m. and 3:30 p.m. on Monday stood at $1.56 billion while the figure from the extended hours -- from 3:30 p.m. to 2 a.m. the next day came in at $230 million, data from to the Bank of Korea showed.

Although the trading volume appears to have decreased significantly during extended hours, the foreign exchange authorities assessed it to be at a fair level, considering that other internationalized currencies that can be traded 24 hours a day also tend to see decreasing trading volume during nighttime hours.

Despite concerns about increased volatility, the market saw ample liquidity and maintained a narrow bid-ask spread, the difference between the bid price and ask price prices.

The opening of the foreign exchange market during night time is part of a plan to advance the domestic foreign exchange market by increasing accessibility of foreign investors into the bond markets is hoped to capitalize on Korea’s strong position.

“In the short term, domestic and foreign investors will have better accessibility to the market. We also expect to see a decrease in the price difference between exchange rates in onshore and offshore markets in the long term,” Kwan Ah-min, an analyst at NH Investment & Securities said.

Kwan said easier access to the market could facilitate the inflow of funds ahead of Korea's potential inclusion in its FTSE World Government Bond Index, a global major bond index in September.

The longer trading hours are a part of the government's reform efforts to make the list.

Korea and India are the only countries among the world's top 10 economies in terms of nominal gross domestic product that have yet to be included in the bond index.

The Korean won weakened against the US dollar, losing 4.3 won to 1,388.8 per greenback as of 5 p.m.