Global stock markets retreated on Friday at the end of a highly volatile week rocked by twists and turns in the Ukraine crisis and concerns about coming interest rate hikes.

Wall Street had already seen a steep drop on Thursday on renewed fears that Russia would soon invade Ukraine, as well as long-running angst about the Federal Reserve's plans to hike interest rates.

US markets ended lower again on Friday, with the Dow shedding 0.7 percent. The S&P 500 and tech-heavy also closed lower, after starting the session briefly in the black.

"I think given the irrefutable downtrend that we're in, it's very hard to find buyers in a market like this," Maris Ogg of Tower Bridge Advisors said.

In Europe, London's FTSE 100, the Paris CAC 40 and Frankfurt's DAX all ended the week in negative territory.

"Markets continue to chop around on these Russia headlines," said Neil Wilson, analyst at Markets.com.

Shellfire rang out near the frontline between government forces and rebel-held territory in eastern Ukraine, as Kyiv and Washington accused Russia of seeking to provoke an incident to falsely justify an invasion.

Russian President Vladimir Putin, who will oversee a ballistic missile drill this weekend, warned of a "deterioration of the situation" in eastern Ukraine, while the United States warned an invasion could come imminently.

The crisis in Ukraine comes as traders continue to contend with the prospect of US interest rates rising sharply this year as the Fed tries to rein in inflation at a 40-year high.

After spending most of last year saying surging prices would be transitory, the US central bank is now in firefighting mode.

But commentators fear it may be behind the curve and will have to act more stringently than previously thought.

New York Fed President John Williams said hiking rates at the Fed's meeting in March is "appropriate," but he does not see a need to raise by more than a quarter-percentage point initially.

Still, he left the door open to faster rate hikes later if needed.

With tensions in Eastern Europe continuing to absorb most of the attention, oil prices rose despite traders' increasing optimism about a deal on Iran's nuclear program that could see it restart crude exports.

"In the absence of a deal, we could already be talking about triple-figure oil prices," noted Craig Erlam, senior market analyst at OANDA trading group.

Ukrainian President Volodymyr Zelensky attends a military drill outside the city of Rivne, northern Ukraine
Ukrainian President Volodymyr Zelensky attends a military drill outside the city of Rivne, northern Ukraine AFP / Aris Messinis

Oil prices rose, with the WTI contract nearing $92.

New York - Dow: DOWN 0.7 percent at 34,079.18 (close)

New York - S&P 500: DOWN 0.7 percent at 4,348.87 (close)

New York - Nasdaq: DOWN 1.2 percent at 13,548.06 (close)

London - FTSE 100: DOWN 0.3 percent at 7,513.62 (close)

Frankfurt - DAX: DOWN 1.5 percent at 15,042.51 (close)

Paris - CAC 40: DOWN 0.3 percent at 6,929.63 (close)

EURO STOXX 50: DOWN 0.9 percent at 4,074.28 (close)

Tokyo - Nikkei 225: DOWN 0.4 percent at 27,122.07 (close)

Hong Kong - Hang Seng Index: DOWN 1.9 percent at 24,327.71 (close)

Shanghai - Composite: DOWN 0.7 percent at 3,490.76 (close)

West Texas Intermediate: UP 0.2 percent at $91.96 per barrel

Brent North Sea crude: UP 1.1 percent at $94.00 per barrel

Euro/dollar: DOWN at $1.1323 from $1.1366 late Thursday

Pound/dollar: DOWN at $1.3593 from $1.3615