Finance Minister Heng Swee Keat resumed his duties on Monday after a gap of three months as he suffered a stroke during a Cabinet meeting, said the Prime Minister's Office (PMO).

The Prime Minister's Office (PMO) said in a statement on Monday that Lawrence Wong, the Minister for National Development, is taking on the position of Second Minister for Finance.

Deputy Prime Minister Tharman Shanmugaratnam, who has been acting as the covering Minister for Finance, will hand over the responsibilities to Heng.

The changes were made after Heng's doctors gave him permission to resume office work. Prime Minister Lee Hsien Loong announced this change during his National Day Rally speech on Sunday.

Lee said the doctors have recommended Heng to avoid contact with crowds for at least a few more months in order to minimize the risk of infection.

"So he can't do his usual community and grassroots work for a while longer but they have given him the go-ahead to do office work, with minimum interaction," PM Lee told Asia One.

He also said that Heng will focus on next year's Budget and the Committee on the Future Economy. Lawrence Wong will help him out with the operational responsibilities of the Finance Ministry.

During a Cabinet meeting on May 12, Heng collapsed from a stroke due to an aneurysm, a localised weakening of a blood vessel. He underwent a successful operation to seal off the aneurysm on the same day of the stroke and was placed in intensive care unit (ICU). Heng was discharged from hospital on June 25.