* Argentine peso extends losses on wider fiscal deficit * Mexico"s peso cuts monthly gains Dec 22 (Reuters) - Most Latin American currencies weakened again on Tuesday as a new fast-spreading strain of the coronavirus that broke out in the United Kingdom raised fears about further damage to the global economy. The Mexican peso and the Colombian peso slid as oil prices dropped towards $50 a barrel on fears the latest restrictions will dent fuel demand. Oil is a top export of the countries. Strict lockdowns went into effect in Britain on Monday to curb the spread of the new strain of the virus, said to be up to 70% more transmissible. It triggered border bans and travel restrictions from several countries. Brazil"s real lagged the most as fears about the virus drove investors to the safety of the dollar. Chile"s peso also dropped 0.3%, tracking weakness in copper prices. However, stock markets in the region rebounded, with Washington"s approval of an $892 billion pandemic relief package helping them recover some of Monday"s losses. An index of Latin American stocks rose 0.7%, with indexes in Sao Paulo and Santiago leading gains. The U.S. Congress approved an $892 billion coronavirus aid package, throwing a lifeline to the nation"s pandemic-battered economy after months of inaction, while also keeping the federal government funded. The Argentine peso dropped 0.3% further breaching its record low in the previous session after it reported a wider fiscal deficit in November. Key Latin American stock indexes and currencies: Latest Daily % change MSCI Emerging Markets 1249.39 -0.61 MSCI LatAm 2409.59 0.41 Brazil Bovespa 116252.27 0.37 Mexico IPC 43055.14 -0.44 Chile IPSA 4229.12 1.59 Argentina MerVal 50765.53 1.207 Colombia COLCAP 1392.08 1.07 Currencies Latest Daily % change Brazil real 5.1593 -0.72 Mexico peso 20.0630 -0.61 Chile peso 727.4 -0.21 Colombia peso 3440.6 -0.34 Peru sol 3.6157 -0.30 Argentina peso (interbank) 83.2400 -0.11 (Reporting by Shashank Nayar in Bengaluru)