SEOUL -- South Korean President Park Geun-hye on Thursday exercised her veto power to block the revised parliamentary law designed to allow the National Assembly to challenge administrative legislation, the presidential office said.

Park said during a cabinet meeting that the revision had an intention of empowering the parliament to intervene in every administration of the government, describing the intention as "not understandable."

It was her first exercising of the veto power since Park took office in February 2013.

The revised bill on the parliamentary law was passed, with more than two thirds in favor, through the parliament on May 29 to grant lawmakers the right to challenge executive enactment such as the government's enforcement ordinance.

President Park had been widely expected to veto the bill as the revision indicated the Park administration subject to parliamentary approval for every administrative enactment.

Under the country's separation of legislative, administrative and judiciary powers, the National Assembly is given the right to enact a law, and the government can implement administrative legislations under the act.

As the president vetoed the bill, the revision would be sent to the National Assembly for the re-voting, in which it would take effect automatically if more than two thirds of lawmakers favor again for the bill with more than half of a quorum in attendance.

Rep. Kim Moo-sung, leader of the ruling Saenuri Party, told reporters that he respects President Park's veto as she considered the revised bill as "unconstitutional," saying it was a matter of interpretation of the law.

The main opposition New Politics Alliance for Democracy plans to boycott all parliamentary schedules, including enactment to counter negative effects of the Middle East Respiratory Syndrome ( MERS) outbreak on the economy.

The MERS infection cases increased to 180 Thursday since the first case was reported on May 20. The death toll rose to 29 as two more patients passed away.

The economy was hit hardest by the MERS fears as consumers refrained from going to public places and delayed even going for shopping.