Kyiv mayor Vitali Klitschko said he had "very good and positive signals" that new weapons would be announced for Ukraine at a meeting of the country's Western allies in Germany on Friday.
The former heavyweight boxer has been at the World Economic Forum in Davos this week as part of a large Ukrainian delegation that is lobbying for more financial aid and modern weapons.
"Let's pay attention in two days," Klitschko told AFP on Wednesday, referring to a meeting of Ukraine's backers at the US-run Ramstein military base in Germany.
"I hope it will be very positive for Ukraine. Unofficially, I have very good and positive signals."
He added: "We need modern weapons. Ukrainian soldiers are very good, motivated in this war, but motivation is not enough. We need modern weapons to defend our homeland from aggression."
Amid rising pressure on German Chancellor Olaf Scholz to authorise the export of heavy German-made Leopard tanks to Ukraine, Klitschko said they "would be very helpful."
Scholz addressed delegates in person in Davos later in the afternoon, with Ukrainian President Volodymyr Zelensky set to follow via videolink shortly afterwards.
Klitschko also paid tribute to Interior Minister Denys Monastyrsky who died in a helicopter crash outside Kyiv on Wednesday, calling him a "young, very creative, good person".
He said Monastyrsky was flying to the scene of a Russian missile attack on the city of Dnipro on Saturday when his helicopter came down, killing 16 people including three children.
"It's a big tragedy... In the next couple of days, we will know exactly the reason why this crash happened," he told AFP.
- Financial aid -
Elsewhere in Davos on Wednesday, Ukrainian First Lady Olena Zelenska met with CEOs and international financial institutions to discuss reconstruction efforts.
"A very clear message that we've heard is that we shouldn't be talking about what we will do when the war ends... We need to start talking about it today because tomorrow will be too late," she told reporters.
She also appealed to people to donate money and gifts-in-kind to her foundation which is providing aid to war-hit Ukrainians from generators to sleeping bags, firewood and laptops.
Living conditions remain extremely difficult for Ukrainians because of Russia's campaign of "ruining our infrastructure to ensure the country descends into darkness and cold," she said.
"In many regions of our country, people are getting electricity only for a few hours a day and in those regions close to the frontlines they are completely cut off from any infrastructure whatsoever," she added.
The European Bank for Reconstruction and Development said it was crucial to help the "Ukrainian people survive this winter", after Russian shelling destroyed critical infrastructure.
Emergency repairs are needed for services including heating, water and electricity, the EBRD's chief economist, Beata Javorcik, told AFP in Davos.
"It's very difficult to function particularly in winter without access to basic utilities," she said.
The EBRD already financed 1.7 billion euros ($1.9 billion) of investment last year to ensure that the country's heat and lights stayed on and trains kept running, Javorcik said.
"By making the conditions as bearable as possible for the Ukrainian population, we are preventing another exodus of people and preserving human capital that will be needed during the reconstruction phase," she said.
Ukraine's reconstruction needs were estimated at $349 billion by the World Bank in September, but a bank official has said the figure would be revised up this year.