Vladimir Putin underwent cancer treatment in April, a classified US report has said.
The high-ranking officials have reportedly said Kremlin insiders are "sensing that the end is near" for the 69-year-old Russian president.
It has been long-rumoured that Putin has been battling health problems such as cancer and Parkinson's.
The three spy chiefs, who are from the Director of National Intelligence, the US Air Force, and the Defense Intelligence Agency, claim that the latest intelligence report on Putin's health show there are concerns about Putin's paranoia to hold on to power.
The intelligence officials said Putin's deteriorating health will make the prospects of nuclear war less likely - but his death will still "cause chaos".
A senior intelligence officer told Newsweek : "Putin's grip is strong but no longer absolute. The jockeying inside the Kremlin has never been more intense during his rule, everyone sensing that the end is near."
While a senior Air Force leader added: "Is Putin sick? Absolutely. But we shouldn't let waiting for his death drive proactive actions on our part. A power vacuum after Putin could be very dangerous for the world."
The Kremlin has not commented on the alleged cancer surgery but insists Putin is in good health.
Last weekend, Russian Foreign Minister Sergei Lavrov dismissed rumours of Putin's ill health in an interview on French TV.
Some reports claim Putin also has Parkinson’s or early-stage dementia.
He has been looking increasingly more frail and bloated in the face in recent weeks.
Images of him sat with a blanket over his knees during the Victory Day parade earlier this month were far from the invincible hard man persona he likes to portray.
Meanwhile, Putin’s failure to attend key engagements and his disappearance during a state TV broadcast has further added fuel to the fire.
MI6 sources have claimed Putin may already be dead amid speculation about the Russian leader's health.
The Daily Star reports that a body double may have been used for recent appearances, as Kremlin cronies would be keen to cover up his death in an attempt to cling on to power.
There have been rumours that the warmonger's health has been deteriorating in recent months, with his face appearing bloated and observer's questioning whether the 69-year-old might have blood cancer.
Senior MI6 bosses say the Russian president has been seriously ill recently, but that his death would likely be covered up.
