New Zealand recorded 21 new cases of COVID-19 on Saturday, with Prime Minister Jacinda Ardern warning the number will go higher in the next few days and urging the Pacific nation to adhere to the lockdown rules. The infections in the community outbreak of the highly transmissible Delta variant now total 51. Of the 21 new cases, 18 are in the largest city, Auckland, and three in the capital, Wellington. Ardern on Friday extended the lockdown for the country of 5.1 million until midnight on Tuesday as the outbreak widened beyond the two key cities. “One of the things that we’ve learned from New South Wales is that the virus can continue to spread during lockdown,” Ardern said of an outbreak in neighbouring Australia’s most-populous state. New South Wales on Saturday logged a record 825 cases as a Delta outbreak surges despite weeks-long lockdown. “No one wants an extended lockdown …