The United Nations warned Friday that Guatemala is facing its worst drought in three decades, and that at least 2.5 million people have been affected by the crisis.

"The country is facing the worst drought in 30 years, which has triggered a food crisis," said Elisabeth Byrs, spokeswoman of the UN Office for the Coordination of Humanitarian Affairs.

"The effects of El Nino have extended the dry spell, which has caused a reduction and loss of agricultural production affecting some 2.5 million people in 21 provinces," she added.

The situation has claimed some 460 lives since the beginning of the year, according to Guatemalan officials, and the country's President Alvaro Colom has declared it a "public calamity."

Most of the deaths occurred in the impoverished northern section of Guatemala bordering Mexico, where more than half of the region's 13 million inhabitants subsist below the poverty line.

OCHA warned that the drought has already hurt the first harvest this year and "if the situation continues as it is, the second harvest will be also seriously affected."

Last week, Guatemala called on the international community to stump up 110 million dollars (75 million euros) to help battle the famine and drought that has struck the Central American nation.