* MSCI ex-Japan gain 0.3 pct, Nikkei jumps 0.8 pct
* U.S., Mexico reach NAFTA deal, turn up pressure on Canada
* Analysts treating the risk rally with caution
* Some major currencies rally against the dollar
By Swati Pandey
SYDNEY, Aug 28 (Reuters) - Asian shares advanced again on Tuesday while major currencies held on to gains amid hopes global tariff tensions were abating as the United States and Mexico made a deal to overhaul the North American Free Trade Agreement.
Investors expect Canada too would agree to the new terms to preserve a three-nation pact, ultimately dispelling the economic uncertainty caused by U.S. President Donald Trump's repeated threats to ditch the 1994 NAFTA accord.
MSCI's broadest index of Asia-Pacific shares outside Japan climbed 0.3 percent for a second straight day of gains. Australian shares added 0.5 percent while Japan's Nikkei jumped 0.8 percent.
New York's S&P 500 and Nasdaq indexes hit record highs and bond yields rose, while prices for copper, considered a barometer of global growth, climbed.
However, some analysts were treating this rally with a degree of caution.
"News of the US-Mexico trade deal has fuelled risk appetite," analysts at ANZ said in a note to clients.
"It is hard to extrapolate much out of it, as the United States continues to treat each country and deal on its own merit. We remain wary of the current rally in risk appetite, and see it as short-lived."
Investors will keep an eye on U.S. economic data with consumer confidence figures due later in the day and the latest estimate for second-quarter gross domestic product expected on Wednesday.
"The NAFTA agreement is clearly a positive to the extent that it reduces the risk of a generalized global trade war," JPMorgan analysts said in a note, though they cautioned it was not automatically positive for the outcome of talks with China.
"Despite this, APAC equities including HK/China should benefit from the weaker U.S. dollar and risk-on moves."
The dollar index paused near one-month lows against major currencies to be last at 94.762.
Against the yen, the greenback held at 111.20.
The euro held near a one-month top at $1.1680.
The Australian dollar, which is often used as a liquid hedge for global growth, hovered around $0.7345 to stay well above a trough of $0.7248.
The Chinese yuan held near a four-week high to the dollar , a day after the country's central bank took steps to support the currency.
Commodity markets showed signs of optimism in global economic growth prospects. Copper, a favoured indicator of industrial momentum, held near a two-week high of $6,112.00 a tonne.
Oil prices were buoyant, with Brent up 25 cents to $0.76.46 a barrel and U.S. crude rising 19 cents to $69.07.
Gold too was firm too with spot prices at $1211.36 an ounce.
Reporting by Swati Pandey Editing by Eric Meijer