John Lee, who is the city's chief secretary for administration, submitted his resignation to Hong Kong's leader Carrie Lam, according to a government statement.
Hong Kong's No. 2 official and a staunch supporter of a Beijing-backed crackdown on pro-democracy activists tendered his resignation on Wednesday amid expectation that he would announce his intention to run for the top job in the semi-autonomous territory.
John Lee, who is the city's chief secretary for administration, submitted his resignation to Hong Kong's leader Carrie Lam, according to a government statement.
Lam said Monday that she would not seek a second term as chief executive, following a rocky five years punctuated by the COVID-19 pandemic, a crackdown on political freedoms and Beijing's growing influence over the territory.
Local media, including the leading South China Morning Post daily, reported that Lee will be the sole candidate to be endorsed by the Chinese government in Hong Kong's leadership race.
He is expected to announce his candidacy when his resignation is approved by the central authorities later Wednesday.
The city's next leader will be selected on May 8 by a committee of about 1,500 people, a majority of whom are pro-Beijing.
Lee, a former career police officer, was named chief secretary in June and previously served as Lam's secretary for security.
He was a staunch supporter of a police crackdown against protesters during several months of massive anti-government protests in 2019.
After the protests were snuffed out, Lee threw his support behind the national security law, which Beijing imposed on Hong Kong in 2020 as a means to target target pro-democracy activists and supporters.
More than 150 people have been arrested under the law, which outlaws subversion, secession, terrorism and collusion with foreign forces in the city's affairs.