Zuma summoned cabinet ministers to a meeting in Cape Town on Tuesday, eNCA television reported, as pressure builds on the embattled 75-year-old leader to quit.
The 2041 Eurobond issue fell more than 0.7 cents to 109.1 cents, its lowest since mid-December according to Thomson Reuters data.
Five-year credit default swaps rose 5 basis points (bps) from Monday's close to 154 bps, according to IHS Markit data.