MOSCOW: The Russian rouble soared on Monday, firming past 75 versus the dollar ahead of crunch talks between Moscow and Washington in Geneva amid fears over a Russian troop buildup near Ukraine, and with investors eyeing mass unrest in neighbouring Kazakhstan.

With trading activity subdued during Russia's New Year's holidays, the rouble was buffeted last week by events in Kazakhstan, where thousands of people have been detained and public buildings torched during mass anti-government protests, the worst unrest in three decades of post-Soviet independence.

By 0806 GMT, the rouble was 1.1% stronger against the dollar at 74.92, firming past 75 for the first time since Jan. 4 and reaching a high of 74.8925.

It had gained 1.4% to trade at 84.86 versus the euro , a six-day high.

The United States and Russia are set to begin fragile negotiations in Geneva on Monday, before talks involving other parties move to Brussels and Vienna later in the week.

Washington hopes the talks can avert the danger of a new Russian invasion of Ukraine without conceding to the Kremlin's expansive security demands, though prospects for a breakthrough are dim.

Promsvyazbank analysts said that progress in Geneva and at other talks with the NATO military alliance this week could see the rouble return to the range of 73-75 versus the dollar.

Inflation and the US Federal Reserve also remain in focus, said BCS Global Markets in a note, with Fed chair Jerome Powell and governor Lael Brainard set to testify before Senate committees this week.

The dollar was stronger as traders bet their appearances and US inflation data, due on Wednesday, would bolster the case for higher interest rates.

Brent crude oil, a global benchmark for Russia's main export, was up 0.4% at $82.10 a barrel, supporting Russian stock indexes.

The dollar-denominated RTS index was up 3.4% to 1,597.4 points.

The rouble-based MOEX Russian index was 0.7% higher at 3,800.2 points.