Under a new resolution, U.N. member states are no longer required to notify the Security Council of arms sales or military support to the DRC government.
However, arms sales to non-governmental armed groups are still banned.
The French-drafted resolution was supported by Russia and China, which are among the countries that sell weapons and equipment to DRC.
"France has heard the requests of the DRC to support capacity building and the reform of the DRC armed forces," France's Deputy U.N. Ambassador Nathalie Broadhurst said in a statement.
The other resolution renewed the mandate of MONUSCO, the U.N. peacekeeping mission in eastern Congo, for one year. This will allow it to provide support for the general elections of December 2023, the French statement said.
DRC praised the decision in a government statement, saying it corrected an "injustice" that was preventing it from defending itself against rebel groups, in particular the M23.
"France has heard the requests of the DRC to support capacity building and the reform of the DRC armed forces," France's Deputy U.N. Ambassador Nathalie Broadhurst said in a statement.
In recent months DRC's government has publicly protested the weapons ban, saying that a shipment of arms intended for its fight against the M23 rebel group had been blocked, without specifying where or by whom.
The situation in Congo continues to constitute a threat to international peace and security in the region, the U.N. Security Council said.
It requested that Congo provide it with a confidential report by May 31, 2023 "detailing its efforts to ensure the safe and effective management, storage, marking, monitoring and security of the national stockpiles of weapons and ammunition, as well as efforts to fight arms trafficking and diversion."
There has been a surge in fighting between the Congolese army and the M23, a Tutsi-led militia formed in 2012, which staged a major comeback this year.