Russia warns West of armed response over Ukraine threats

Russia is prepared to take military steps in response to "unfriendly" Western actions over the Ukraine conflict, President Vladimir Putin has warned, in a sharp escalation of rhetoric.

Putin also called for "serious negotiations" on Russian security demands put to the United States and NATO during his first call with new German Chancellor Olaf Scholz on Tuesday, who in turn called for "de-escalation".

"What the US is doing in Ukraine is at our doorstep... And they should understand that we have nowhere further to retreat to. Do they think we’ll just watch idly?" Putin said.

The Russian president has for weeks accused the United States and the Washington-led NATO military alliance of stoking tensions near Moscow's borders, but these were his first comments hinting at potential conflict.

Putin told Defence Ministry officials that if the West continued its "obviously aggressive stance" Russia would take "appropriate retaliatory military-technical measures".

Russia "will react toughly to unfriendly steps", he said, adding that he wanted to underscore that "we have every right to do so".

"The chancellor expressed his concern about the situation and spoke of the urgent need for de-escalation," said a statement released by Scholz's office.

'Doorstep of our house'

The United States has been sounding the alarm since mid-November that Moscow could be planning a large-scale attack on its ex-Soviet neighbour Ukraine and has warned Putin of unprecedented sanctions.

Western governments have accused Moscow of amassing some 100,000 troops near its border with eastern Ukraine, where Kiev has been fighting pro-Russia separatists since 2014. 

Russia denies plotting an invasion and has demanded legal guarantees over its security from the United States and NATO, demanding the alliance stop an eastward expansion.

Despite hinting at conflict, Putin insisted Russia wanted to avoid "bloodshed".

"We want to resolve issues by political and diplomatic means," he said.

But the Russian leader repeated grievances over Washington's support for Ukraine, which includes training Kiev's forces and committing more than $2.5 billion in funds to them.

Those actions are taking place "at the doorstep of our house", said Putin.

READ MORE: No, Russia is not going to launch a mass invasion of Ukraine

US mercenaries preparing chemical weapon provocations

Also on Tuesday, the Russian defence chief accuses US mercenaries of preparing chemical weapon provocations in Ukraine.

Sergey Shoygu said some 120 US mercenaries are now working in Ukraine's war-torn Donbas region, training the Ukrainian military "for active combat operations."

"It has been reliably established that there are more than 120 employees of American private military companies in the settlements of Avdiivka and Priazovskoye in the Donetsk region," he told a meeting of the Russian Defence Ministry board in Moscow.

"They equip firing positions in residential buildings and socially significant facilities, train Ukrainian special operations forces and radical armed groups for active combat operations."

The private firms also delivered "tanks with unidentified chemical components" to the cities of Avdiiv ka and Krasny Estuary "to commit provocations," Shoygu claimed.

READ MORE: Why Ukraine matters to Russia so much