Aug 20 (Reuters) - The Reserve Bank of New Zealand's balance sheet will continue to grow as it supports the economy and financial system in response to the COVID-19 pandemic, a senior official said on Thursday.

Reserve Bank of New Zealand (RBNZ) Assistant Governor Christian Hawkesby said the implications of COVID-19 were not yet over as he outlined possible "next steps" with the country's official cash rate already at a record low 0.25%.

Among possible policy options, the RBNZ is considering taking the cash rate into negative territory for the first time ever, a funding for lending programme, foreign assets purchases, and interest rate swaps, Hawkesby said. (Reporting by Swati Pandey in Sydney; Editing by Chris Reese)