Russia has likely sent nuclear weapons to Belarus' Lida Air Base, 40 kilometres from the border with Lithuania, the US newspaper wrote on Sunday, citing open-source intelligence.
The WSJ added that "Putin wants to scare NATO into ending its military support for Ukraine."
"Putin's provocative nuclear move in Belarus is a reminder of what is at stake in Ukraine," the US daily said.
Belarusian Hajun, which tracks military activity in Belarus, said The WSJ did not provide specific evidence of the presence of Russian tactical nuclear weapons in Belarus, the RBC-Ukraine news agency reported.
On Christmas Day, Belarus' strongman leader Alexander Lukashenko said that Russia had completed its shipments of tactical nuclear weapons to his country, the Associated Press news agency reported.
Lukashenko added the deployment had been wrapped up in October, without specifying how many weapons were sent or where they had been stationed.
It comes as Russia has sharpened its rhetoric towards the West, with Putin warning there would be "problems with Finland" after its accession to NATO, the RBC-Ukraine news agency reported.
In November, Russia's Deputy Security Council Chairman Dmitry Medvedev referred to Poland as an "enemy," warning it could lose its statehood.
In May 2023, Russia and Belarus signed an agreement on the deployment of Russian tactical nuclear weapons in Belarus amid "growing threats on their western borders," Moscow officials said at the time.
In June, Russian President Vladimir Putin said that Russia had delivered the first batch of its tactical nuclear warheads to Belarus, adding that the deployment would be completed by the end of the year.
The initiative raised strong concerns in neighbouring Poland and elsewhere in the region, the AP news agency reported.
Tuesday is day 685 of Russia’s war on Ukraine.
Russia invaded Ukraine on February 24, 2022, launching the largest military campaign in Europe since World War II.
Source: The Wall Street Journal, RBC-Ukraine, AP