South Korea's leading doctors' body on Saturday rejected a revised medical reform plan from the government, the initial version of which sparked a strike two months ago.

The ongoing walkout by thousands of trainee doctors has caused chaos in South Korean hospitals, and is in response to a plan to boost annual admissions to medical schools by 2,000 from next year.

The government on Friday offered its first concession, allowing 32 universities to admit as few as 1,000 medical students instead of the initially proposed 2,000 – but the Korean Medical Association (KMA) said the plan must be abandoned entirely within a week.

"Since this is not a fundamental solution, the emergency committee of the Korean Medical Association clearly states that it cannot accept it," Kim Sung-geun, a KMA spokesperson, told reporters.

"For the sake of our country's future and to protect the health of patients currently suffering, we ask the president... to discuss this again from square one."

Kim said "one week is left" to find a solution.

The government claims its plan will alleviate doctor shortages for an ageing society, but medical professionals and trainees say it will diminish the quality of education and healthcare.

The strike, which began on February 20, has forced hospitals to cancel essential treatments and surgeries.

On top of the trainee doctors, who play a key role in emergency procedures and surgeries at general hospitals, more than 50 percent of the country's medical students have also filed for a leave of absence, according to the education ministry.

The KMA warned that if the government does not relent, medical students will likely be forced to repeat a year, senior doctors at general hospitals will start to resign on April 25, and the healthcare system could "collapse."

The government's Friday offer came after President Yoon Suk-yeol's conservative ruling party suffered a crushing defeat in parliamentary elections this month.

Initially, there was public sympathy for the government, but polls leading up to the April 10 election indicated that the mood had shifted.

Nearly 60 percent of people surveyed in a Dong-A Ilbo poll said the government should adjust the scale and timing of its reform plan.

The main opposition Democratic Party has also criticised Yoon and urged him to revise the reform plan.

The government had previously warned of legal consequences if doctors did not return to work, and suspended the medical licences of two KMA officials purportedly for instigating the walkout.

Proponents of the plan say opposing doctors are simply trying to safeguard their salaries and social status. (AFP)