KYIV - U.N. Secretary-General Antonio Guterres said on Friday there was still much more to do to ensure full global access to Ukrainian food products and Russian food and fertilisers after a U.N.-brokered food export deal.

At a briefing in Ukraine's Black Sea port of Odesa, Guterres said developing countries needed help to purchase such grain and called for unimpeded access to global markets for Russian food and fertilisers which are not subject to sanctions.

"This is an agreement between two parties locked in bitter conflict. It is unprecedented in scope and scale. But there is still a long way to go on many fronts," he said.

"It is time for massive and generous support so developing countries can purchase the food from this and other ports – and people can buy it," he said.

(Reporting by Pavel Polityuk and Andrea Shalal; writing by Tom Balmforth; editing by Jason Neely)