The rand was flat early on Monday, but its recent resilience in the face of hawkish signals from global central banks could be tested by warnings that Russia could invade Ukraine at any time.
At 0637 GMT, the rand traded at 15.2200 against the dollar, the same as its close on Friday.
The United States on Sunday said Russia might create a surprise pretext for an attack on Ukraine, as it reaffirmed a pledge to defend "every inch" of Nato territory.
Analysts at ETM Analytics said the rand had been supported of late by South Africa's strong terms of trade, relatively high real yields and fresh reform pledges by President Cyril Ramaphosa.
But the standoff over Ukraine has the potential to rock global markets, they said in a research note.
Other potential drivers this week include January consumer inflation numbers and December retail sales on Wednesday.
Economists polled by Reuters predict annual inflation will ease to 5.7 percent in January from 5.9 percent in December, while retail sales will rise 2.2 percent year on year in December compared to 3.3 percent in November.
Both releases will provide further clues about price pressures and the health of Africa's most industrialised economy, as markets try to predict whether the South African Reserve Bank will raise its main lending rate for the third-consecutive time at its next monetary policy meeting in March.
The government's benchmark 2030 bond was also little changed early on Monday, with the yield at 9.19 percent.
REUTERS