KYIV, April 5 (Reuters) - Ukraine's armed forces said they had repelled 45 Russian attacks during the past 24 hours as fighting raged in and around the city of Bakhmut, while Washington pledged more weapons to help Kyiv prepare for a spring counteroffensive.

After weathering a punishing, months-long assault in eastern Ukraine, Kyiv's military commanders have said a counteroffensive is not far off but have stressed the importance of holding towns, including Bakhmut, and inflicting losses in the meantime.

"The question of our counter-attack is under active discussion by American and European political circles - perhaps to excess," said Serhiy Zgurets, director of the publication Defense Express.

Ukrainian diplomats will have to convince allies that a single advance pushing Russian troops back will not be sufficient for victory, he wrote on the Espreso TV website.

"It will mean training our soldiers in NATO member-states, securing the equipment and ammunition we need and planning to determine when and where to start the counter-attack, or if it should be in several places at once."

The United States on Tuesday unveiled $2.6 billion more in military assistance for the government of President Volodymyr Zelenskiy, including three air surveillance radars, anti-tank rockets and fuel trucks. The U.S. has now provided more than $35 billion in military aid to Ukraine since Russia's invasion.

"The main thing is not to lose time, not to lose the chance we have. Act now, help now," Zelenskiy told the U.S. National Governors Association by video link. "Ukrainians act so that Americans don't have to fight - and together we gain new strength for our countries."

The Russian embassy in Washington accused the United States of wanting to drag out the conflict as long as possible, Russian news agency TASS said.