SEOUL, Jan. 18 (Xinhua) -- South Korean President Moon Jae-in's approval rating fell for two straight weeks on rising controversy over the government's regulation on cryptocurrency trading, a survey showed Thursday.

According to the Realmeter poll, support for Moon was 67.1 percent this week, down 3.5 percentage points from the previous week. It marked the fall for the second consecutive week.

It was based on a survey of 1,507 voters conducted from Monday to Wednesday. It had 2.5 percentage points in margin of error with a 95 percent confidence level.

The government sought to regulate the trading of cryptocurrencies, including Bitcoin, bringing backlash from traders and ordinary people participating in the transactions.

Cryptocurrencies recently surged in values, encouraging ordinary people to join the trading, which the government sees as speculative investment.

Support for Moon's ruling Democratic Party fell 2.7 percentage points over the week to 48.9 percent this week, but it kept its top post by a wide margin.

The main opposition Liberty Korea Party came second with 17.9 percent in support scores, followed by the minor progressive Justice Party with 6.3 percent.

The minor conservative Righteous Party and the centrist People's Party gained 6.1 percent and 5.5 percent each in approval rating.