US Vice President Joe Biden will announce $100 million to improve access to mental health services when he meets Tuesday with families of children killed in the Newtown school shooting, an official said.

Half the money will go to enable community health centers to offer behavioral health services to people suffering from mental illness or addiction, according to an administration official.

Another $50 million will be earmarked by the Department of Agriculture for the construction of mental health facilities in rural areas, said the official, who asked not to be identified.

"The vice president will discuss the new funding during a meeting at the White House with families who lost loved ones during the shooting in Newtown, as well as mental health advocates," the official said.

On Saturday, the United States marks the first anniversary of the massacre at the Sandy Hook Elementary School in Newtown, Connecticut, which left 26 people dead, including 20 six- and seven-year-old children.

The shooter, a mentally unbalanced 20-year-old, committed suicide at the scene.

The killing, two weeks before Christmas, traumatized the United States and ignited renewed debate over the country's lax gun laws.

A handful of states have since toughened their laws, but national reforms advocated by President Barack Obama failed to pass the US Senate.

Obama, who entrusted the fight against gun violence to Biden after Newtown, has vowed to tackle the problem using decrees and administrative measures.