U.S. stock index futures were sharply higher on Friday after Greece made substantial concessions in its latest bid to win new funds from creditors and avert bankruptcy.

Greek Prime Minister Alexis Tsipras appealed to his party's lawmakers to back a tough reforms package that won praise from France, which called the new proposals "serious and credible".

Greece has asked for $59 billion to help cover debts until 2018 and has pledged new tax hikes in return. Euro zone finance ministers will meet on Saturday to decide whether to recommend opening negotiations for a third bailout for Athens.

Global markets were also supported by a continued recovery in China's stock market, which rose strongly for a second day, helped by a barrage of government support measures.

Over the past two weeks Chinese authorities have cut interest rates, suspended IPOs, relaxed margin lending and collateral rules and enlisted brokerages to buy stocks, backed by cash from the central bank.

Investors will also look for clues regarding the timing of an interest rate hike in the United States, when Federal Reserve Chair Janet Yellen speaks at a conference in Cleveland, Ohio. Yellen, scheduled to speak at 12:30 p.m. ET (1630 GMT), will give her views on the prospects for U.S. growth, inflation and the job market.

Zillow's shares fell 2.6 percent to $83.01 in premarket trading, a day after the company said its chief financial officer is leaving the company to pursue other business interests.

Futures snapshot at 7:01 a.m. ET:

S&P 500 e-minis were up 25.75 points, or 1.26 percent, with 233,940 contracts traded.

Nasdaq 100 e-minis were up 54.5 points, or 1.26 percent, on volume of 34,100 contracts.

Dow e-minis were up 189 points, or 1.08 percent, with 34,380 contracts changing hands.