New York will give patients with certain serious illnesses faster access to medical marijuana under legislation signed Wednesday by Gov. Andrew Cuomo while the state works out the details of its full medical cannabis program.

The measure will create an expedited approval process for people facing degenerative diseases and those who further face the risk of death or serious harm without the drug. It also authorizes state health officials to work with regulated producers who can provide marijuana to patients as soon as possible.

New York's wider medical marijuana program is expected to be operational in January -- a full 18 months after lawmakers approved it.

People with AIDS, terminal cancers and the parents of children with severe epilepsy have long sought early access, arguing that critically ill individuals shouldn't have to wait any longer.

The bill posed a conundrum to Cuomo, a Democrat who has favored a cautious and conservative approach to medical cannabis. In a statement announcing his approval of the bill, he wrote that the state must ensure that early access to the drug doesn't run afoul of federal law -- or jeopardize the state's wider program by violating federal law.

"I deeply sympathize with New Yorkers suffering from serious illness and I appreciate that medical marijuana may alleviate their chronic pain and debilitating symptoms," Cuomo wrote. "I am also mindful, however, of the overarching authority, jurisdiction and oversight of the federal government."

Advocates for medical cannabis said expedited access to the drug will be especially important to patients if the implementation of the law gets pushed back.

"We are very pleased that the governor did the right thing today," said Julie Netherland, deputy New York state director for the Drug Policy Alliance. "For us, the proof will be when patients can get the medicine they need."

The state's program will already be one of the most tightly regulated in the country when it begins operations. The marijuana will be required to be in the form of a tincture, oil or other non-smokable form that can be ingested or vaporized. Qualifying conditions include cancer, AIDS, Parkinson's, Lou Gehrig's disease and epilepsy.

The state in July picked five companies to grow and dispense the marijuana. The companies will each operate one cultivation facility and four dispensaries. Of the 20 dispensaries, four are planned for New York City, four for the suburbs and 12 for upstate.

Cuomo said Wednesday that the state's Department of Health will examine the locations of approved marijuana dispensaries to see if additional locations are needed to ensure statewide access.