South Korea ordered striking cement truck drivers back to work on Tuesday, a rare move that Seoul said was necessary because industrial action posed a danger to the economy.

A broader truckers' strike, which started Thursday over minimum pay, is generating an estimated 300 billion won ($226 million) in daily losses, according to interior minister Lee Sang-min.

The strike -- the second major industrial action in less than six months -- has again triggered concerns about the impact on global supply chains, already strained by prolonged Covid-19 lockdowns in China and Russia's invasion of Ukraine.

While the walkout was organised by the 25,000-strong Cargo Truckers Solidarity Union, the back-to-work order only affects drivers specifically in the cement industry -- around 1,000 of those involved in the action.

The government said the construction sector had been particularly hard-hit by the truckers' strike, prompting the rare intervention.

Due to the strike, "cement shipments plummeted by more than 90 percent, and ready-mixed concrete construction was suspended at about 50 percent of construction sites," finance minister Choo Kyung-ho told reporters, also slamming "illegal" actions to attack non-striking truckers.

Tuesday's back-to-work order was issued by conservative President Yoon Suk-yeol, who accused the striking drivers of "threatening the daily lives of people" and jeopardising South Korea's industrial base.

This is the first time such an order has been imposed since it was codified under the Trucking Transport Business Act in 2004.

"There is no justification nor rationale for taking people's lives and the national economy hostage in order to achieve their own interests," Yoon told a cabinet meeting.

The order was necessary to avoid a more serious economic crisis, Yoon said.

Truckers who fail to comply with the order may be punished with jail terms of up to three years and have their licences suspended, among other penalties.

The truckers' union slammed the government's decision, accusing it of "ordering us to die".

"The government made a decision to limit the basic rights of truckers by holding our livelihoods hostage," it said in a statement.

With fuel prices rising, the drivers have been demanding the government make permanent the "safe freight rate" minimum pay scheme, which is set to expire at the end of the year.

The government said last week it would extend the programme for three years but truckers say more of them will become vulnerable to overwork and safety risks without a permanent minimum wage guarantee.

"Hundreds of truck drivers have died of a heart attack inside a running vehicle. All of the cases have been counted as 'traffic accidents'," the union said.

Negotiations were set to continue Wednesday after not reaching an agreement on Monday.