(Recasts throughout, updates prices) By Susan Mathew Dec 3 (Reuters) - Latin American stocks and currencies rose on Monday as risk appetite got a boost from a temporary truce in the Sino-U.S. trade war, with Brazil shares hitting yet another record high. Over the weekend, U.S President Donald Trump reached an agreement with his Chinese counterpart Xi Jinping to hold off on new tariffs for 90 days at the Group of 20 summit in Argentina. The MSCI index of Latin American equities climbed to an over three-week high, while the currency index rose 1 percent with the Argentine peso firming more than 3 percent against a weaker dollar. In addition to a ceasefire in the Sino-U.S. trade war, Gustavo Rangel, chief LATAM economist at ING, attributes the day's rally to a dovish turn in the U.S Federal Reserve last week and regional assets being cheaper due to a recent sell-off. But, Rangel warned that while there is room for some opportunistic, end-of-the-year rally, "it's not that EM are out of the woods." "It's hard to imagine that things are resolved. The Sino-U.S. deal looks more like a truce than a resolution. The Fed is also a key component for future risk appetite. If markets really recover, will the Fed return (to being hawkish)?" On the day, the Mexican peso a weather vane for trade sentiment, was up 0.2 percent, having hit its highest in more than thee weeks earlier in the session. The weekend also saw the country's new president, leftist Andres Manuel Lopez Obrador (AMLO), take office and reassure investors after markets crashed last month on worries about his policies. The peso and stocks got an additional boost as AMLO's government launched a plan to buy back some of the debt issued to fund the construction a partly built airport in Mexico City, the cancellation of which had set off the decreasing investor confidence in the new administration. In Brazil, the real gained 0.6 percent, while stocks hit a new all-time high for a third straight day. Commodity stocks led gains with iron ore miner Vale and state-oil firm Petrobras rising, in tandem with higher iron ore and oil prices respectively. Morgan Stanley analysts said that since tariffs have been held back for the time being, "within the EM bloc, investors may now switch from commodity-consuming towards commodity-producing FX which, in the high-yield spectrum, may lend support to LatAm currencies." Argentine assets outperformed their regional peers returning from a three-day weekend, with the peso up 3.26 percent, and stocks hitting their highest in a month, up 1.3 percent. "Argentine assets are super risky - so it rallies more when risk appetite returns," ING's Rangel said. Gains were bolstered also by the country's central bank signing a deal with China on Sunday to extend a currency swap by $8.6 billion, bringing the total swap amount to $18.69 billion. Key Latin American stock indexes and currencies at 2129 GMT: Stock indexes Latest Daily YTD pct pct change change MSCI Emerging Markets 1016.87 2.23 -12.22 MSCI LatAm 2641.79 1.62 -6.59 Brazil Bovespa 89820.09 0.35 17.56 Mexico IPC 42076.98 0.82 -14.75 Chile IPSA 5151.67 0.78 0.78 Argentina MerVal 31888.79 1.29 6.06 Colombia IGBC 12083.40 4.12 6.27 Currencies Latest Daily YTD pct pct change change Brazil real 3.8410 0.02 -13.74 Mexico peso 20.3380 0.29 -3.14 Chile peso 668.8 0.55 -8.10 Colombia peso 3187 1.43 -6.43 Peru sol 3.381 0.03 -4.26 Argentina peso 36.4800 3.59 -49.01 (interbank) Argentina peso 35.75 2.80 -46.21 (parallel) (Reporting by Susan Mathew in Bengaluru; editing by Jonathan Oatis)