Chinese President Xi Jinping has declared victory after a 15-month-long austerity campaign that cut $8.6 billion in public spending, state media said, as he pledged not to relent against official corruption.

The "mass line" initiative -- a Maoist term for the need to align the ruling Communist Party with the people -- saw more than 160,000 "phantom" government employees removed and 74,000 party members punished for violating austerity rules, the official Xinhua news agency said.

The completion of the drive was marked with a conference attended by all seven members of the Politburo Standing Committee, China's most powerful body, and broadcast live to government officials and military officers, the state-run Global Times newspaper reported Thursday.

"The close of the campaign is not the end of good work styles," Xinhua quoted Xi as saying.

The Global Times said the initiative, which began in June 2013, had targeted "undesirable work styles such as formalism, bureaucracy, hedonism and extravagance".

Xinhua said it led to a 25 percent reduction in official meetings, the retrieval of more than 100,000 excessive government vehicles and a 1.9 million reduction in the number of official documents circulated.

New Chinese leaders have regularly launched anti-corruption drives, and since taking office last year, Xi has ordered an end to excessive gift-giving and banquets within the state sector, amid rising anger among the Chinese public at widespread official greed.

A related graft crackdown has led to a series of high-profile takedowns of party officials that have sent shockwaves through an elite who once did little to hide their prosperity.

News of the "mass line" campaign's close comes less than two weeks ahead of a highly-anticipated conclave known as the Fourth Plenum, at which party leaders will set policy goals and focus on the chosen theme of "rule of law".

The state-run China Daily newspaper ran an editorial Thursday praising the austerity drive and calling on Xi to continue the momentum.

But it also warned that "the more successful such thorough and forceful actions are, the more corrupt the Party and government appear to be".

"With the fight going even further, sometimes a dozen or more corrupt elements in the same government department end up being investigated for abuse of power, as one rotten apple can spoil others in a barrel," the paper wrote.

Despite "malicious" attempts to use such examples to smear the reputation of the party and government, "the leadership's zero-tolerance to corruption will become increasingly obvious and welcomed by the public", it added.