SEOUL, South Korea (AP) — South Korea’s impeached president defended his martial law decree as a desperate bid to promote public awareness of the danger of the opposition-controlled parliament, and vowed Tuesday to push for political reform if reinstated.

President Yoon Suk Yeol made his final statement at the Constitutional Court as it wrapped up oral arguments in his impeachment trial. The court is expected to rule by mid-March on whether to remove Yoon from office or reinstate his presidential powers.

The liberal opposition-controlled National Assembly impeached Yoon, a conservative, after his Dec. 3 martial law decree plunged the country into political turmoil, shook its financial markets and hurt its international image. He has been separately arrested and indicted on rebellion charges in connection with his short-lived decree. The rebellion charge carries the death penalty or life imprisonment if convicted.

Yoon has denied any wrongdoing and blamed the main liberal opposition Democratic Party, which obstructed his agenda and impeached top officials, for the political crisis. During his marital law announcement, Yoon called the assembly “a den of criminals” and “anti-state forces.”

“The reason why I declared martial law was because of a desperation as I could no longer neglect a do-or-die crisis facing this country,” Yoon said. “I tried to inform the people of these anti-state acts of wickedness by the mammoth opposition party and appealed to the people to stop it with their surveillance and criticism.”

After declaring martial law, Yoon sent troops and police officers to the assembly, but enough lawmakers still managed to enter an assembly chamber to vote down Yoon’s decree unanimously, forcing his Cabinet to lift it.

Yoon insists that he had no intentions of disrupting assembly work and that deploying troops and police was meant to maintain order. But some commanders of military units sent to the assembly have told assembly hearings or investigators that Yoon ordered them to drag out lawmakers to prevent them from overturning his decree.

Massive rallies by opponents and supporters of Yoon have divided the streets of Seoul and other major South Korea cities. Whatever the Constitutional Court decides, experts say it will likely further polarize the country and intensify its conservative-liberal divide. If Yoon is formally thrown out of office, a national election must take place within two months to find his successor.

During more than an hour of testimony Tuesday, Yoon said that he would push for political reforms and a constitutional revision to change the current presidential system, if he regains his presidential powers.

He suggested he could step down early before his single five-year terms ends in 2027 in the course of promoting political reform. It’s unclear whether and how Yoon’s statement could affect the court's ruling.

South Korea adopted the current system that limits a president to a single five-year term in 1987, ending decades of military-backed dictatorships. After Yoon’s martial law stunt, there have been calls to change it. Some favor a parliamentary Cabinet system, others want a U.S.-style setup in which a president can run for a second four-year term, or a system in which a president and prime minister split key responsibilities.