MOSCOW, July 12 (Reuters) -

The Kremlin said on Friday that the whole world had paid

attention to Joe Biden's verbal slips at a NATO summit and said

the way the U.S. president had spoken about Russian President

Vladimir Putin was unacceptable.

The Kremlin was commenting after Biden on Thursday misspoke

and introduced Ukrainian President Volodymyr Zelenskiy as

"President Putin", before quickly correcting himself. In another

slip, Biden mixed up the names of Kamala Harris, his

vice-president, and his election opponent Donald Trump.

"We noticed that the whole world paid attention to what

happened, and there can be no comment here (from us), but it is

clear that these were slips of the tongue," Kremlin spokesman

Dmitry Peskov told reporters.

"It is understandable that they probably received such a

wide resonance given the context of the internal political

discussions that we are now witnessing in the US, but

it's not our topic, it's an internal U.S. topic," he said.

Biden's stumbling performance in a debate with Trump

last month and subsequent further slips have spurred intense

debate about his mental fitness, at 81, to run for a second

term, and led some Democrats to call for him to stand aside.

Peskov said it was for U.S. voters, not Russia, to

determine the U.S. presidential candidates' prospects.

But he added that the Kremlin had taken note of what it

called disrespectful comments Biden had made about Putin.

He did not say what those comments were, but Biden referred

to Putin at the NATO summit as "a murderous madman."

"We continue to consider it absolutely unacceptable and

impermissible behaviour for a head of state to make such

disrespectful remarks about other heads of state. I am referring

to his remarks about President Putin," Peskov said.

"This is unacceptable to us, and we don't think it in

any way makes an American head of state look good. This is

something that we pay direct attention to and something that is

absolutely unacceptable to us."

The Kremlin has accused Biden in the past of making

unseemly comments about Putin. Biden assented in 2021 to a TV

interviewer's description of Putin as "a killer", and in

February this year called the Kremlin leader a "crazy SOB".