Humanitarian aid currently flows into Syria across UN-designated checkpoints without the formal permission of the regime in Damascus, but that authority is due to expire on January 10.
Germany, Belgium and Kuwait presented a resolution extending that authority for a year, winning the support of 13 council members but drawing the vetoes from Russia and China.
A competing Russian resolution that would have granted a six month extension while reducing the number of UN crossing points was rejected, having failed to get the minimum nine votes.
Russia is a close ally and major supporter of Syrian President Bashar al-Assad, and has used its veto 14 times on Syrian issues since the start of the civil war in 2011.
It was the second time in four months that it has vetoed a resolution dealing with the humanitarian situation in the country.
Russia's ambassador to the United Nations, Vassily Nebenzia, said the latest resolution was "obsolete" because the authorities in Damascus have "retaken control of most of the territory" of Syria.
Anne Gueguen, France's deputy permanent representative, called the Russian veto "irresponsible" and "grim," insisting there was no alternative to providing aid across Syria's borders.
Kelly Craft, the US ambassador, also accused Moscow of irresponsibility and cruelty.
In September, Moscow used its veto against a resolution calling for a ceasefire in the region of Idlib in northwestern Syria. That resolution also was sponsored by Germany, Belgium and Kuwait.
The text vetoed Friday called for a one-year extension of the authorization to ship humanitarian relief supplies into Syria -- in effect since 2014 -- through three checkpoints, two in Turkey and one in Iraq.
Hoping to overcome Russian opposition, the resolution's sponsors on Wednesday dropped a request for a fourth point of entry on the Jordanian border, which has hardly been used since 2018.
Earlier in the week, Russia offered a competing draft resolution calling for a six month extension, but at only the two Turkish checkpoints.
Put to a vote Friday, it was rejected, with the United States, France, the United Kingdom, Poland, Peru and the Dominican Republic voting against. Germany, Belgium, Kuwait and Indonesia abstained.
Four million Syrians directly benefit from the cross-border aid shipments while 11 million benefit from international aid after eight years of war.
The UN humanitarian relief department says the aid remains crucial as the situation on the ground has deteriorated over the past year and Syria is heading into winter.