The U.S. is hurting Russia. Russia has not (yet) hurt the U.S.

If you read the news, you will often see reports of Ukraine attacking sites in Russia.

Some of the attacks, likely a few, are using drones made either in Ukraine or China.

But the vast majority of the strikes are using weapons made in the U.S., notably the ATACMS

https://en.wikipedia.org/wiki/MGM-140_ATACMS .

Some strikes have been carried out by cruise missiles made in GB or France 

https://en.wikipedia.org/wiki/Storm_Shadow

And Ukraine has requested the German Taurus 

https://en.wikipedia.org/wiki/Taurus_KEPD_350 .

But the vast majority of the strikes have been made by missiles made in the USA.

The Russians are well aware of this.

"Russia blames US for Crimea deaths and vows response"

https://www.bbc.com/news/articles/c6pppr719rlo

It seems to me the Russians are essentially right on this.

The U.S. supplies Ukraine with the weapons it uses to attack Russia, 

also, it is said U.S. personnel are involved with both preparation of the missiles and their targeting, 

and the U.S. has made no objection to the weapons it has supplied being used to attack Russia.

All this, effectively makes the U.S. a cobelligerent with Ukraine in the Russia-Ukraine war.

And this justified, IMO, the claim that the U.S. is harming Russia.

(Of course, outside of the world of kinetic weapons, the U.S. is openly trying to harm Russia through sanctions.)

OTOH, where has Russia ever tried to harm the U.S.?

I am not aware of any such efforts.

If  Russia does now try to harm the U.S., 

either directly or through surrogates,

they will no doubt claim that is just retaliation for the harm the U.S. has caused Russia.

Based on the above, 

it certainly looks to me like they would be right.

-------

Russia issues threat:

https://www.politico.com/news/2024/06/29/russia-ukraine-offensive-00165926

"... has brought new threats by President Vladimir Putin to retaliate against the West — either directly or indirectly.

...

Washington and some NATO allies have responded to the [Russian] offensive by allowing Kyiv to use Western weapons for limited strikes inside Russia.

...

[Putin] declared that just as the West says Ukraine can decide how to use Western weapons, 

Moscow could provide arms to North Korea and 

“similarly say that we supply something to somebody but have no control over what happens afterward” — 

an apparent hint at Pyongyang’s role as arms trader.

Dmitry Medvedev, the deputy head of Russia’s Security Council, noted Moscow could arm anyone who considers the U.S. and its allies their enemies, “regardless of their political beliefs and international recognition.” "