At 0635 GMT, the currency was 0.34 percent weaker against the dollar at 13.38/dlr.

In a morning note, analysts at Nedbank said "a combination of local and external factors are capping rallies in the local currency," including disappointing tax collection and escalating US/China trade tensions.

Technical resistance seen at 13.30, support at 13.61/dlr.

Domestic data this week includes June manufacturing numbers which will provide some pointers about the strength or weakness of economic growth.

Bonds softer, with the yield on the benchmark paper due in 2026 up 1.5 basis points to 8.70 percent.