Immediate action from the international community is needed to stem the growing food crisis in Niger, relief groups say.

"We must act now and provide food to the people of Niger who are struggling in this terrible humanitarian crisis," Noel Wardick, head of the Irish Red Cross, said before his departure to the country on Tuesday.

Severe droughts last year, which left bad harvests and killed grazing lands for livestock, have caused a major famine in the country, deemed the worst of its kind in decades.

Some 3.3 million people in Niger, or one fifth of the country's population, are at risk of "severe food insecurity," according to the U.N.

The country's first heavy rains of the year, which began earlier this month, were a mixed blessing to Nigeriens as they hastened the death of many herders' sickly cattle.

"Our generation has never experienced such a situation and it is well beyond anything we anticipated," Dodo Boureima, head of the Niger Association for the Revival of Breeding told IRIN.

The International Federation of Red Cross (IFRC) has issued a $3.1 million appeal in response to the situation. Catholic Relief group Caritas Internationalis has asked for $3.5 million.

"It's not too late to avert a tragedy," said Raymond Yoro, secretary general of Caritas Niger. "Donors must immediately give the resources governments in the Sahel and aid agencies need."

Wardick, however, noted that farmers must also be supplied with seeds for the current planting season and feed for animals so that they don't experience a similar fate next year.

Niger, a landlocked country near the Sahara desert, faced previous famines in 1984 and 2005.