The South African rand was under pressure early on Tuesday as uncertainty surrounding the Iran war hung over markets ahead of the release of domestic mining figures and key US inflation data.

At 0632 GMT, the rand traded at 16 4575 against the dollar, a whisker away from its previous close, and teetering near a more than two-week low.

Statistics South Africa is due to publish May mining production data, at 0930 GMT, offering fresh insights into the health of Africa's largest economy.

Mining production rose 8.2% year-on-year in April, with economists polled by Reuters expecting it to have moderated to 1.5% this time around.

The US dollar crept lower against a basket of currencies as investors awaited inflation data later in the day and testimony by Federal Reserve Chair Kevin Warsh on the central bank's semi-annual monetary policy report to Congress.

Traders also remained focused on developments in the Gulf after US President Donald Trump said Washington was reinstating its blockade of Iranian shipping and would levy a 20% fee on cargo passing through the Strait of Hormuz.

South Africa, a net fuel importer, has proposed a revamp of its strategic fuel storage capability requiring mandatory reserves from both the State and private sector to mitigate supply disruptions.

South Africa's benchmark 2035 government bond was weaker in early deals, as the yield rose 7.5 basis points to 8.42%.