Japan will withdraw 350 Self-Defense Forces engineering troops from South Sudan by the end of May, ending its participation in a U.N.-led peacekeeping operation that has been in place for over five years, Prime Minister Shinzo Abe told reporters Friday.

Meanwhile, SDF personnel dispatched to the U.N. mission’s headquarters in Juba, South Sudan’s capital, will remain.

Later Friday, Chief Cabinet Secretary Yoshihide Suga denied that Japan will withdraw the unit because of deteriorating security conditions.

Suga said security conditions in the capital, where the SDF units are now deployed, “have been stable” and relatively safe.

Under the peacekeeping operations law, popularly known as the PKO law, Japan can dispatch an SDF unit to a U.N.-led peacekeeping mission only if a cease-fire agreement among conflicting parties is maintained.

Many observers have argued this condition is no longer being met in South Sudan, but the government has maintained there are no security problems as far as Juba is concerned.

“We understand the security situation (of South Sudan) is still very severe, but conditions in the capital city are relatively stable,” Suga told a news conference.

“We are not withdrawing because of security reasons,” he emphasized.

According to the government, Japan has dispatched a total of 4,000 SDF troops to Juba since January 2012.

The troops have repaired a total of 210 km of road and finished preparing 500,000 sq. meters of land so that construction projects can be started, the government said.

This month, the SDF unit is scheduled to finish carrying out repairs to major roads around the capital. With that in mind, the government has been considering whether or not to withdraw the unit since last fall, a senior official later said.

Facing reporters at the Prime Minister’s Office, Abe maintained that the South Sudanese government and U.N. “highly value” Japan’s contributions to the peacekeeping mission and are thankful.

In the future, Japan will keep dispatching SDF units to “international peace cooperation activities” by advocating “pro-active contributions to peace,” Abe said.

The South Sudan government now plans to launch “national dialogue” to facilitate talks among ethnic groups in the country later this March.

This steps toward talks mark the beginning of a new stage of building political stability, which was also a factor in Tokyo’s decision to withdraw its troops, government officials said.