The United States on Tuesday warned Russia of damaging sanctions, including high-tech export curbs, and said attempts by Moscow to "weaponize" its enormous oil and gas industry would backfire.

"We are prepared to implement sanctions with massive consequences" that go far beyond previous measures implemented in 2014 after Russia invaded Ukraine's Crimea region, a senior US official said.

"The gradualism of the past is out," the official told reporters, speaking on condition of anonymity. If Russia orders a new invasion of Ukraine, "we'll start at the top of the escalation ladder."

Addressing concerns in Europe that Russia could push back against sanctions by curbing its own energy exports to heavily dependent Europe, the official said Russia would also be hurting itself.

"If Russia decides to weaponize its supply of natural gas or crude oil, it wouldn't be without consequences to the Russian economy," a senior US official told reporters.

Although the European Union sources about 40 percent of its supply from Russia, Moscow also relies heavily on sales of energy for its national budget, meaning "it's an interdependency," the official said.

The United States and its European allies are scouring global markets for alternative energy sources to mitigate fallout from any conflict, as Europe already finds itself struggling with soaring mid-winter energy prices.

Prices for fuel are rising across Europe, including at this Paris filling station
Prices for fuel are rising across Europe, including at this Paris filling station AFP / Thomas COEX

"We're working with countries, companies around the world to ensure the security of supply and to mitigate against price shocks," the official said.

The "contingency planning" includes negotiations with suppliers in North Africa and Asia to "temporarily surge gas output."

Liquid natural gas tankers have already started rerouting from Asia, bringing "a significant impact on the resilience of energy supply in Europe," according to the official.

The economic sanctions being prepared to respond to any Russian invasion of Ukraine would include previously unused restrictions on exports of high-tech US equipment, the official said.

"What we're talking about are sophisticated technologies that we design and produce," the official told reporters.

This would include artificial intelligence, quantum computing and aerospace technologies and would "hit (President Vladimir) Putin's strategic ambitions to industrialize his economy quite hard."

"These are sectors that Putin himself has championed, as the way forward for Russia to diversify its economy beyond oil and gas," the official said.

"And in many, many instances, if Russia wants to develop these sectors, it needs to import technologies and products that only we and our allies and partners produce."