SEOUL, South Korea (AP) — North Korean leader Kim Jong Un was given a new title, “general secretary” of the ruling Workers’ Party, a post held by his late father and grandfather, state media reported Monday, a largely symbolic appointment apparently aimed at bolstering his authority amid growing economic challenges at home.

The party’s ongoing congress, the first in kind in five years, announced Kim’s new title during its sixth-day session on Sunday. A congress statement said Kim “has gloriously realized the historic mission to complete the country’s nuclear build-up plan," according to the official Korean Central News Agency.

It's largely seen as a symbolic move as Kim has already been the party’s top leader. During a 2016 party congress, he was named to “party chairman," largely the equivalent of “general secretary” held by his father Kim Jong Il and grandfather “Kim Il Sung.” Before the 2016 congress, Kim Jong Un had led the party with the title of “first secretary.”

Since taking power in late 2011, Kim has taken up a slew of top posts and established the similar absolute power enjoyed by his predecessors. The two late North Korean leaders have kept posthumous titles — Kim Jong Il remains “eternal general secretary” and Kim Il Sung is “eternal president.”

On Sunday, state media said the congress had determined to change the party’s “Executive Policy Council into Secretariat.” The decision would lead to party officials to relinquish the current titles such as chairman and vice chairman and start using old titles such as secretary or vice secretary.

The congress is being held as Kim faces what appears to be the toughest moment of his nine-year rule because of multiple blows to his country’s already-fragile economy caused by pandemic-related border closings that have drastically reduced external trade, a series of natural disasters and U.S.-led sanctions.

During the congress, Kim Jong Un vowed to enlarge his nuclear arsenal and build more sophisticated weapons systems to cope with what he calls intensifying U.S. hostile policy. He also admitted a previous five-year economic development plan failed and disclosed a new development that focuses on building a stronger self-reliant economy.