Ukrainian President Volodymyr Zelensky said Monday the situation for his troops was improving having "halted" Russian advances on the front, as Kyiv rejected Pope Francis's suggestion to negotiate with Moscow.
More than two years since Russia launched its invasion, Kyiv has faced mounting pressure on the front line in recent months, losing ground to Moscow amid hold-ups to Western aid from its biggest ally Washington.
But on Monday, Zelensky told French broadcaster BFM TV, "The Russian advance has been halted."
"Our command, our military has stopped the Russian advance in eastern Ukraine," he said.
His comments followed anger over a suggestion by Pope Francis at the weekend that "the strongest are those who see the situation, think about the people and have the courage to raise the white flag and negotiate".
The pope's comments to Swiss broadcaster RTS sparked a furore and met with sharp criticism from Germany, as well as Kyiv.
On Monday, the Ukrainian foreign ministry summoned the Vatican's envoy, Visvaldas Kulbodas, in response to tell him Kyiv was "disappointed with the words of the Pontiff".
The ministry said the Catholic leader's words "encourage them (Russia) to further disregard international law."
The Ukrainian leader also said that troops were in the process of building "over 1,000 kilometres (621 miles)" of fortifications.
"When we talk about fortifications, we're talking about an ongoing process," Zelensky said. "We're not talking about a few kilometres, or hundreds of kilometres, but more than 1,000 kilometres of construction."
He called it a "complex task."
"They must be solid and resistant to changes in the climate (...) but also resistant to whatever military hardware is used against these defensive lines," he said.
In contrast to the Pontiff's calls, Poland made an appeal to NATO allies to up their spending on defence in response to Russia's aggression.
"I want to propose in the near future... that NATO members decide together that the alliance requirement will be to spend not two percent, but three percent of GDP on defence," Polish President Andrzej Duda told reporters Monday.
Poland already spends around four percent.
Duda said NATO must give a "clear and courageous response to Russian aggression".
"This response will consist of increasing the military capacity of the North Atlantic Alliance," he added.
Hold-ups to Western aid -- mainly a crucial $60-billion package from the United States -- have left Ukraine's troops in a vulnerable position, forced to ration ammunition and unable to mount large-scale offensives.
Despite this, Zelensky said Monday: "I can give you this fresh piece of information: The situation is now much better than during these past three months."
In reference to a comment by French President Emmanuel Macron, who last month said that sending French troops to Ukraine was not ruled out, Zelensky said: "As long as Ukraine holds, the French army can stay on French territory".
As tensions remain high over aid to Kyiv, Hungary's Prime Minister Viktor Orban said that former US president Donald Trump told him during a meeting that he would "not give a penny" to the war in Ukraine.
Orban -- the only EU leader to have maintained ties with the Kremlin since Russia invaded Ukraine -- travelled to Florida on Friday to meet his "good friend" Trump. He has frequently expressed hope for the Republican's return to power.
Speaking to public broadcaster M1 late Sunday, Orban said the two men spoke about Ukraine during their Friday meeting at Trump's Mar-a-Lago residence, and that Trump had "quite detailed plans on how to end this war", declining to elaborate.
Trump's team did not comment on the claim.
