Biden's national security advisor held secret talks with Russia warning against using nukes in Ukraine: WSJ

• Biden's National Security Advisor held talks with Kremlin officials, per The Wall Street Journal.
• Jake Sullivan warned Russia against using nuclear weapons in Ukraine, its report said.

White House National Security advisor Jake Sullivan held secret talks with senior Russian officials to warn them against using nuclear weapons in Ukraine, The Wall Street Journal reported.

US and allied officials told the publication that in recent months Sullivan had held talks with Yuri Ushakov, a foreign policy adviser to Russian President Vladimir Putin, as well as Nikolai Patrushev, head of Russia's security council.

The intention from the US was to avoid the war in Ukraine escalating further, potentially to the point that Russia deploys part of its nuclear arsenal.

The talks came amid concerns that Russia could resort to the use of tactical nuclear weapons in Ukraine, following a series of setbacks on the battlefield.

In a televised address in September, Russian President Vladimir Putin warned the West that he was not bluffing when he said he'd be ready to use nuclear weapons to defend Russia.

The New York Times reported last week that Russian military leaders had discussed using them.

Ukraine in recently months forced Russia's military into retreat in the east of the country, and the Kremlin has launched a chaotic mobilization of civilians amid heavy battlefield casualties.

In remarks on October 27, Putin said Russia was not intending to use nuclear weapons, and US and other Western intelligence agencies say they've not detected any signs of the military getting nuclear weapons ready.

Amid the threat of nuclear war, US and Russian military officials have held discussions in a bid to avoid miscommunications that could result in the war spreading beyond Ukraine.

Top military officials Mark Milley, chairman of the joint chiefs of staff, and Valery Gerasimov, chief of the Russian general staff, have recently been in private communication, while US Defense Secretary Lloyd Austin and his Russian counterpart Sergei Shoigu have also held talks.

But diplomatic relations have overall been limited in the wake of the invasion, and the last time President Joe Biden and Putin communicated was in February, when Biden warned Putin against following through with his invasion plans.