An El Nino-induced drought has wilted crops across Zimbabwe and left about a third of its 15 million people in need of food assistance, according to a U.N. agency.
The situation was worsened when Zimbabwe, along with Mozambique and Malawi, was last month battered by Cyclone Idai, leaving hundreds of thousands needing food, water and shelter.
An appeal document given to reporters by the ministry of information showed the government is seeking about $300 million in aid for food while the rest would fund emergency shelters, logistics and telecommunications among other needs.
Hundreds of people have died in Mozambique and Malawi and the death toll in Zimbabwe was now 344.
Meanwhile, Information Minister Monica Mutsvangwa said the cabinet had hiked the maize price paid to farmers by 86 per cent to $232 a tonne and maintained a subsidy for millers in a bid to keep the price of the staple maize meal down.
In February, Zimbabwe scrapped a 1:1 peg between the U.S. dollar and the bond notes and electronic dollars it introduced to compensate for its hard currency shortage, merging the surrogate currencies into the RTGS dollar.
Mutsvangwa said farmers would be paid 726 RTGS dollars ($232), up from 390 RTGS dollars.
The RTGS dollar was trading at 3.12 to the U.S. dollar on Tuesday on the bank market and at 4.4 on the black market.
The government is the sole buyer and seller of maize in Zimbabwe through the state-owned Grain Marketing Board.