By Jonathan Landay and Humeyra Pamuk
WASHINGTON (Reuters) - Waves of Russian strikes on Ukraine's electrical grid have failed to dim its determination to resist Moscow, but Washington and its allies need do more to help the country keep the power on, a senior U.S. diplomat said on Monday.
"I think this strategic bombing campaign ... has clearly failed in its attempt to break the will of the Ukrainian population," Assistant Secretary of State Geoff told Reuters three days after returning from talks in Kyiv.
Pyatt's comments came hours after Russia launched "kamikaze" drones at electrical infrastructure in and around the Ukrainian capital, the latest in a series of strikes that have left millions without power as temperatures drop below freezing.
The attacks, which began in October as Russia suffered a string of battlefield defeats following its February invasion, have destroyed at least 50%of the country's power infrastructure, according to the United Nations.
Washington and its allies have pledged tens of millions of dollars to repair and replace targeted equipment while supplying air defense systems that have helped Ukraine protect critical infrastructure from Russian missiles and drones.
Pyatt, a former U.S. ambassador to Ukraine who coordinates support for its electrical infrastructure, said Ukrainians have shown "extraordinary adaptability" by cannibalizing and moving power equipment as well as protecting transmission stations with earth-filled barriers.
The first two tranches of equipment from a $53 million U.S. energy aid package arrived in Ukraine last week, he said, and some already has been deployed.
"Clearly we need to do more," Pyatt said, noting that U.S. President Joe Biden has asked Congress to approve $1.1 billion to support the energy sectors in Ukraine and neighboring Moldova, which is seeking to break its dependence on Russian natural gas.
Ukraine's most urgent request, he said, is for equipment to keep its power grid operating, including transformers that handle "super high voltage" current.
Such transformers, however, are in short supply and require long lead times to build. Those found in the United States cannot be adapted to the Ukrainian system, necessitating a global hunt for such equipment.
He spoke last month in Japan with Toshiba Corp and Hitachi Ltd about supplying high-voltage transformers, to "underline for them the priority we place on this effort" and urge them to expedite deliveries, he said.