President Vladimir Putin said captured Nato military hardware will be the subject of study for Russian specialists, who would look to “reverse engineer” such equipment.
His comments come after the West promised a new tranche of weaponry for Kyiv as its attempts to stage a major offensive in the south and west of the country.
“There is such an expression as 'reverse engineering,” Mr Putin said in an interview with state television. “If there is an opportunity to look inside to see if there is something there that can be applied in our country, well, why not?”
During the interview, he also hailed Russia's military hardware, praising the T-90 Proryv tank as an example.
“The best tank in the world! Without any exaggeration. But the enemy also produces cutting-edge equipment,” Mr Putin said.
On Monday, Russia's Foreign Ministry revealed that Kerch Bridge, which links Crimea to mainland Russia, had been severely damaged in a suspected drone attack.
Images showed a section of the bridge had collapsed, leading to it being closed to civilian traffic. The bridge had suffered serious damage in another explosion in October.
“Today's attack on the Crimea bridge was carried out by the Kyiv regime,” Russian Foreign Ministry spokeswoman Maria Zakharova said on social media.
A Ukrainian military intelligence source said that its waterborne drones were responsible for the attack, Reuters reported.
Rossiya TV reporter Pavel Zarubin published excerpts of the interview to his Telegram channel on Sunday before a scheduled broadcast on Sunday night.
In another excerpt, Mr Putin said that the Ukrainian counter-offensive had been futile.
“All attempts by the enemy to break through our defences … they were unsuccessful during the entire offensive,” he said. “The enemy is having no success.”
500 days of war in Ukraine – in pictures
On Friday, Ukraine conceded it had encountered difficult battles.
“Today, it's advancing not so quickly,” the head of Ukraine's presidential office, Andriy Yermak, told reporters.
Kyiv said its troops had advanced nearly 2km along the southern front over the past week.
Ukrainian Deputy Defence Minister Ganna Malyar said “the situation has somewhat intensified in the east”.
“For two days in a row, the enemy has been actively attacking in the Kupiansk sector in the Kharkiv region. We are on the defence,” Ms Malyar wrote on Telegram.
However, Ukrainian forces are “gradually moving forward” near the eastern city of Bakhmut, which Russian forces seized in May, she said.
Bakhmut, once home to 70,000 people and known for its sparkling wine and salt mine, has been destroyed by the longest and bloodiest battle of the war.
“In Bakhmut itself, we are shelling the enemy, and the enemy is shelling us,” Ms Malyar said.
But the use of the bombs by both sides has been widely documented and cluster rounds have been found after strikes.
“Until now, we have not done this, we have not used it and we have not had such a need,” Mr Putin said.
The Pentagon said on Thursday that cluster munitions provided by the US had arrived in Ukraine.
The munitions, which are bombs that open in the air and release scores of bomblets, are regarded by the US as a way to get Kyiv critically needed ammunition to help bolster its offensive and push through the Russian front lines.
US leaders debated the thorny issue for months before President Joe Biden made the final decision last week.
Cluster bombs have long been criticised by humanitarian groups, and some US allies, because those used in previous conflicts have had a high “dud rate”.
That means they often leave behind unexploded bomblets that can harm civilians long after a battle has ended.
Proponents argue that Russia has already been using cluster munitions in Ukraine and that the weapons the US is providing have been improved to leave behind far fewer unexploded rounds.
Ukraine has promised to use them only away from densely populated areas.