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 $US2.6 billion ($A3.9 billion) more in military assistance for the government of President Volodymyr Zelenskiy, including three air surveillance radars, anti-tank rockets and fuel trucks. The US has now provided more than $US35 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 US 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.
Tens of thousands of Ukrainian civilians and soldiers on both sides have been killed in what Russia calls a "special military operation" to rid the neighbouring nation of Nazis. It claims to have annexed nearly a fifth of Ukraine.
The West calls the war an unprovoked assault to subdue an independent country and has provided Kyiv with weapons while seeking to punish Russia with sanctions.
The battle for Bakhmut has been one of the bloodiest of the conflict, with heavy casualties on both sides and the city largely destroyed.
The founder of Russia's Wagner mercenary force, Yevgeny Prigozhin, recently claimed his forces had captured the mining city and logistics hub.
Ukraine has repeatedly denied Russians control the city, while acknowledging they have taken at least half of it.
"In the Bakhmut sector, there was no let-up in enemy actions aimed at storming the city of Bakhmut. At least 20 enemy attacks were repelled here alone over the past 24 hours," the Ukrainian general staff said in a report on Facebook.
Reuters could not verify the battlefield reports.
Ukraine on Tuesday welcomed the accession to the NATO alliance of Finland, which shares a 1300km border with Russia, 13 months after Russia invaded Ukraine, partly in response to what Russia called the alliance's aggressive expansion eastward.
"I congratulate all the people of Finland," Zelenskiy said in his evening address. "Russian aggression clearly proves that only collective guarantees, only preventive guarantees, can be reliable."
Russia's invasion of Ukraine prompted the Finns - after decades of strategic non-alignment - to seek security under the umbrella of NATO's collective defence pact, which states that an attack on one member is an attack on all.
Russia, which has watched successive waves of NATO enlargement since the Cold War ended three decades ago, has also said it would strengthen its military capacity in its western and northwestern regions in response to Finland's accession.
Separately, the Kremlin said Belarussian President Alexander Lukashenko would travel to Moscow on Wednesday for two days of talks with Russian President Vladimir Putin.
