The South African rand was flat in early trade on Friday as a stronger US dollar continues to dominate trading, with investors also focused on upcoming US inflation data for clearer signals on the Federal Reserve's next move.

At 0717 GMT the rand traded at 16.1325 against the dollar, little changed from its previous close of 16.15.

The greenback climbed to a near one-month high against a basket of currencies as investors awaited key US inflation data later in the day.

The rand often takes cues from global drivers such as US policy in addition to domestic economic data.

"The ZAR has had a tough week, steadily losing ground. It comes amid a trade-weighted USD that has steadily gained ground amid escalating geopolitical risks," said ETM Analytics in a research note.

US President Donald Trump warned Iran that it must reach a deal over its nuclear programme or "bad things" will happen, and appeared to set a 10-day deadline before the US might take action.

"The US's posture towards Iran has some investors spooked that it may impact oil production, and Brent crude oil prices touched $72.0p/b overnight. The implication is that it could keep inflationary pressures elevated and affect interest rates, which, in turn, would negatively impact stock markets," said ETM Analytics.

On the Johannesburg Stock Exchange, the Top-40 index was last up 0.5% in early trade.

South Africa's benchmark 2035 government bond was firm in early deals, as the yield fell 5 basis points to 7.985%.