By Olena Harmash
KYIV (Reuters) -Russia struck Ukrainian ports a day after pulling out of a U.N.-backed deal for safe Black Sea grain exports, and Moscow and Kyiv gave vastly different accounts of fighting in northeastern Ukraine on Tuesday.
Russia said it hit fuel storage in Odesa and a plant making seaborne drones there, as part of "mass revenge strikes" for attacks by Ukraine that knocked out its road bridge to the occupied Crimean Peninsula.
Shortly after the bridge was hit on Monday, Moscow withdrew from the year-old grain agreement, a move the United Nations said risked creating hunger around the world.
At the United Nations on Tuesday, U.N. spokesman Stephane Dujarric said there were a "number of ideas being floated" to help get Ukrainian and Russian grain and fertilizer to global markets. Moscow's decision raised concern primarily in Africa and Asia of rising food prices and hunger.
The Black Sea deal was brokered by the U.N. and Turkey in July last year to combat a global food crisis worsened by Russia's February 2022 invasion of Ukraine and its blockade of Ukrainian ports. The two countries are among the world's top grain exporters.
For Ukraine's part, "we are fighting for global security and for our Ukrainian farmer" and working on options to keep commitments on food supply, President Volodymyr Zelenskiy said in his nightly video address.
Moscow spurned calls from Ukraine to allow shipping to resume without Russian participation, with the Kremlin openly saying ships entering the area without its guarantees would be in danger.
"We're talking about an area that's close to a war zone," Kremlin spokesman Dmitry Peskov said. "Without the appropriate security guarantees, certain risks arise there. So if something is formalised without Russia, these risks should be taken into account."
Russia says it could return to the grain deal, but only if its demands are met for rules to be eased for its own exports of food and fertiliser. Western countries call that an attempt to use leverage over food supplies to force a weakening in financial sanctions, which already allow Russia to sell food.
BLASTS ROCK PORT BUILDINGS
Falling debris and blast waves damaged several homes and unspecified port infrastructure in one of Ukraine's main ports, Odesa, according to Ukraine's southern operational military command. Authorities in Mykolaiv, another port, described a serious fire there.
Ukraine's air force said six Kalibr missiles and 31 out of 36 drones were shot down. Moscow, for its part, said it had foiled a Ukrainian drone strike on Crimea, with no major damage on the ground, and reopened a single lane of road traffic on the Crimea bridge.
Six weeks since Ukraine launched a counteroffensive in the east and south, Russia is mounting a ground offensive of its own in the northeast. Moscow says the Ukrainian assault has failed.
A Russian Defence Ministry spokesman said its forces had advanced by up to 2 km (1.2 miles) in the direction of Kupiansk, an important railway junction in the northeastern Kharkiv region.
But Ukrainian Deputy Defence Minister Hanna Maliar said the initiative in the area had switched to Ukrainian forces.
She said Ukrainian forces made new gains near Bakhmut in the east, a town that was captured by Russian forces in May after months of battles.
Valery Shershen, a spokesperson for Ukrainian troops on the southern front, reported heavy fighting around the village of Staromayorske. "We have made advances through the streets," Shershen told the Espreso TV online outlet but said Ukrainian forces did not have complete control of the village.
Russian Defence Ministry accounts said Moscow's forces had hit groups of Ukrainian soldiers around Staromayorske.
Reuters could not independently verify the battlefield reports of either side.
Since Ukraine began its counteroffensive last month, its forces equipped with billions of dollars worth of new Western weapons and ammunition have yet to attempt a major breakthrough across heavily defended Russian lines.
The top U.S. general said Ukraine's counteroffensive was far from a failure, but predicted a long haul.
"I think there's a lot of fighting left to go and I'll stay with what we said before: This is going to be long. It's going be hard. It's going to be bloody," General Mark Milley, the chairman of the Joint Chiefs of Staff, told reporters in Washington.
Both sides have endured bitter losses in Europe's bloodiest combat since World War Two, yet front lines have moved only incrementally since last November, despite a Russian winter assault followed by Ukraine's counteroffensive.
(Reporting by Reuters bureaus; Writing by Peter Graff, Alex Richardson and Grant McCool; Editing by Angus MacSwan, Willaim Maclean and Daniel Wallis)