The time is near to negotiate peace in Ukraine to reduce the risk of another devastating world war, but dreams of dismembering Russia could unleash nuclear chaos, the patriarch of US diplomacy Henry Kissinger said, quoted by Reuters.

Kissinger, who was the architect of the Cold War policy of detente with the Soviet Union as secretary of state under Presidents Richard Nixon and Gerald Ford, has met Vladimir Putin on several occasions since he became Russia's president in 2000.

So far, there is no way out of the conflict that began with the Russian invasion of Ukraine on February 24, in which tens of thousands of people have been killed and millions forced to flee their homes.

Russia currently controls nearly a fifth of the territory of Ukraine, according to Reuters.

The Kremlin says Kyiv must recognize Moscow's annexation of four southern and eastern Ukrainian regions it partially controls.

Ukraine is demanding that all Russian troops leave its territory, including the Crimean peninsula, which Russia annexed in 2014. Ukraine applied to join NATO after Moscow announced the annexation of those areas in September. 

The war in Ukraine: Heavy fighting in Bakhmut

"The time is approaching to build on the strategic changes and integrate them into a new structure aimed at achieving negotiated peace," Kissinger wrote in the Spectator magazine.

"A peace process must link Ukraine to NATO in a definitive way. The neutrality alternative will no longer make sense," Kissinger said in an article titled "How to Avoid Another World War."

He noted that in May he proposed a cease-fire in which Russian forces would withdraw to their pre-invasion positions and the fate of Crimea would be subject to negotiation.

"Dismembering Russia, or destroying its ability to conduct strategic policy, could turn its territory spanning 11 time zones into a contested vacuum," Kissinger wrote.

"Her rival communities may decide to settle their disputes by force. Other countries may try to expand their claims by force. All these dangers will be compounded by the presence of thousands of nuclear weapons, which make Russia one of the two largest nuclear states in the world," Kissinger added.