By Hideyuki Sano

TOKYO (Reuters) - U.S. stock futures jumped in early Asian trade on Monday after Greek Prime Minister Alexis Tsipras offered a new package of reforms to foreign creditors - a ray of hope for a last-minute deal at the emergency euro zone summit meeting later in the day.

But many investors were still cautious because it was not immediately clear how far the new proposal yielded to creditors' demands for additional spending cuts and tax hikes, nor whether creditors can stomach the offer.

"Greece will be reaching a climax this week and markets will be extremely nervous. The markets are on the whole moderately hopeful on a deal. But it is difficult to tell the outcome as this will be a highly political decision," said Masakazu Kabeya, chief global strategist at Daiwa Securities.

U.S. stock futures (ESc1) price rose 0.5 percent from Friday's close to 2,107.75. The euro (EUR=) also ticked up 0.2 percent to $1.1366, inching closer to a one-month high of $1.1440 hit on Thursday.

U.S. Treasuries futures (TYc1) fell 8.5/32 or 0.2 percentage point in price to 126-10.5/32 as hopes rose, erasing Friday's nervous gains.

The Nikkei futures (NIYU5) contract in Chicago is trading almost flat from Tokyo close on Friday.

Locked out of bond markets and with bailout aid frozen since summer last year, Athens is running out of cash to repay a 1.6 billion euro IMF loan due at the end of the month unless it gets new financing from international creditors.

Speculation is rife that, if no deal were reached on Monday, Greece may need to impose capital controls on Tuesday to avert a banking crisis as savers keep withdrawing funds from banks.

Bank of Greece Governor Yannis Stournaras met senior bankers on Friday and told them to brace for a "difficult day" on Tuesday if no deal is reached, two bankers at the meeting told Reuters.

Giving some temporary relief for regional markets, Chinese mainland markets will be closed on Monday for a holiday, after posting their biggest weekly loss since 2008 last week.

For bulls, that was a long overdue correction as Chinese shares have risen more than 40 percent so far this year at one point. But some others fret further falls in stock prices could stoke concerns about slowdown in the Chinese economy.

Elsewhere, copper futures (CMCU3) hit three-month low of $5,652 a tonne last week on worries about demand in top metals consumer China and uncertainty in the Greek debt talks.