Drafted by the United States, the resolution received 12 votes in favour, with the three above countries abstaining.
The Council additionally scheduled a midterm review to take place by December 15 and expressed its "readiness to consider adjusting measures... including through modifying, suspending, lifting or strengthening".
The Security Council was also asked to provide a report by the end of October on the role of the arms embargo in implementing a 2018 peace agreement as well as provide options for developing benchmarks.
South Sudan President Salva Kiir and Riek Machar, the rebel leader who is now first vice president, reached a deal to form a unity government in February but remain at odds over issues including who will govern the country's 10 internal states.
South Sudan is emerging from a brutal six-year civil war that left 380,000 dead and millions displaced.
In a statement on Friday, Amnesty International welcomed the renewal of the arms embargo.
"It is crucial to curtailing the flow of weapons that have been used to commit war crimes, human rights violations and abuses," said Deprose Muchena, the group's director for East and Southern Africa, calling on all UN members to apply the embargo.