MOSCOW: The rouble weakened to a more than one-week low against the dollar on Thursday ahead of a phone call between President Vladimir Putin and his US counterpart, Joe Biden, at a time of strained Moscow-Washington relations over Ukraine.

At 0744 GMT, the rouble was 0.4% lower against the dollar at 74.29, its weakest since Dec. 22.

It was down 0.3% at 84.10 against the euro, close to a one-month low hit in the previous session.

The rouble has been under increased geopolitical pressure since October as Western nations have expressed concerns about Russia's military build-up near neighbouring Ukraine. Moscow says it can move its army around its own territory as it deems necessary.

Putin and Biden will speak at 2030 GMT as Washington crafts a common response with European allies to Russia's military moves near Ukraine, with upcoming security talks between Moscow and Washington slated for discussion.

The rouble may well approach the 75 mark versus the greenback, said Alor Broker in a note, in part because a favourable tax period that usually prompts export-focused companies to convert their forex revenue into roubles to meet local liabilities has passed.

Trading activity has faded and is expected to stay below average until Jan. 10, the end of Russia's New Year holidays.

The Moscow Exchange will be closed on Dec. 31 and resume trading on the forex market on Jan. 3.

Brent crude oil, a global benchmark for Russia's main export, was down 0.3% at $79.00 a barrel.

Russian stock indexes were mixed.

The dollar-denominated RTS index was down 0.1% at 1,588.8 points, while the rouble-based MOEX Russian index was 0.1% higher at 3,745.1 points.