JOHANNESBURG, March 31 (Reuters) - South Africa’s rising long term bond yields and the related cost of government borrowing remain a concern, ratings firm S&P Global said in its second quarter economic outlook for emerging markets. The yield on South Africa’s benchmark 2030 government bond hit a record-high above 13% in March 2020 at the height of the financial crisis triggered by the coronavirus pandemic. Yields came down as the central bank slashed lending rates and launched a bond-buying programme. But they have started rising again in 2021, to near the 10% mark, as climbing Treasury yields in the United States lured away lenders. “In South Africa, 10-year domestic currency government bond yields have risen about 70 basis points this year. While less abrupt, the rising cost of funding presents a challenge, given that interest rate payments in South Africa are already among the highest among key EMs,” said S&P in a release dated March 30. S&P said this month that the 2021 budget did not focus enough on economic reforms, making a sustained rebound in gross domestic product unlikely. The deficit is forecast to more than double to 14% of gross domestic product in the 2020/21 fiscal year, from 5.7% in the previous year. Foreign investors have avoided the country’s bonds or demanded a high premium, or yield. The central bank said on Tuesday non-residents had sold 74.6 billion rand of bonds in 2020. Year-to-date, foreign selling of local bonds was 28.5 billion rand, according to Johannesburg Stock Exchange data. The Reserve Bank (SARB) last week resisted raising lending rates following hikes by other emerging market central banks, saying the inflation outlook was benign. The bank said it had little control over long-term bond yields. S&P said in the report the increasing divergence between the U.S. rebound and the rest of the world could “force central banks to implement defensive interest-rate hikes” to compensate for the growing yield differential, especially those countries with large fiscal deficits like South Africa. (Reporting by Mfuneko Toyana; Editing by Alison Williams)