The United States, Britain and France on Wednesday asked that a Russian request to send light arms to the Central African Republic be put on hold as they seek more information on the shipments, diplomats said.
Russia has asked the UN Security Council for an exemption to an arms embargo on the Central African Republic (CAR) to allow the arms to be shipped to its armed forces.
The first delivery of pistols, automatic rifles and ammunition is scheduled for next week.
CAR President Faustin-Archange Touadera asked Russian Foreign Minister Sergei Lavrov for the weaponry during talks at the Black Sea resort of Sochi in October.
Russia is proposing to supply the arms for two battalions totalling 1,300 men, who were recently trained by the European Union.
A council diplomat said the three countries had requested additional information, but did not block the request.
"Our only request was that the Russian delegation submit additional information on the serial numbers of the weapons ...so that we can track weapons going into CAR," said a US official.
"We think it is a reasonable request and underscores the importance of coordinating the physical protection, control, safe storage, and management of transferred arms and ammunition."
"We asked for additional information and did not oppose this request," said a spokesperson for the British mission.
France blocked a previous request last month over concerns about the storage of the weapons in the volatile country, a council diplomat said.
The Central African Republic has been struggling to return to stability since the country exploded into bloodshed after the 2013 overthrow of long-time leader Francois Bozize by the mainly Muslim Seleka rebel alliance.
France intervened militarily to push out the Seleka alliance but the country remains plagued with violence pitting groups competing for control of resources and areas of influence.
According to the request obtained by AFP, Russia said the light arms would be stored under tight security and new storage units could be provided for the arms that will be kept in the provinces, where most clashes are taking place.
A first shipment is planned for Monday, with two others set for February 1 and April 1. It remained unclear if the deliveries would go ahead as scheduled.
Among the weapons on the list are 900 pistols, 5,200 assault rifles, 140 sniper rifles, 840 Kalashnikov machine guns, 270 RPGs and 20 anti-aircraft guns.
Russia would also provide millions of rounds of ammunition including armour-piercing cartridges, hand grenades and mortars, the document said.
Russian defence ministry officials travelled to CAR last month to review the newly trained forces and discuss the military aid.
"Having assessed the situation in CAR, the Russian side agreed with the opinion of this country's leadership on the necessity to increase the overall strength of the armed forces of the Central African Republic," said the request from the Russian mission to the United Nations.