U.S. stock index futures point to a higher open Tuesday as investors continue to expect the European Central Bank to implement new policy measures to rejuvenate the euro zone economy. 

Futures on the Dow Jones Industrial Average were up 0.25 percent, those on the Standard & Poor's 500 index were up 0.31 percent, while the Nasdaq 100 index futures were up 0.48 percent.

Investors are likely to focus on the euro zone's debt burden, especially Spain and Italy's "crippling" borrowing costs, according to Reuters. Market players continue to hope the ECB will enact bond purchases to alleviate the debt pressure on those two countries.

On a positive note, German Chancellor Angela Merkel's government indicated it would support the ECB's move to buy bonds. Such a bond purchase by the ECB requires the explicit agreement of all member states, including ratification by the German Parliament.

The Federal Reserve will release its consumer credit report on Tuesday, which measures the change in the total value of the outstanding consumer credit that requires installment payments. Experts forecast it to be $11 billion in June, as compared to $17.12 billion in May.

U.S. stocks rose Monday as investor sentiment continued to be upbeat on expectations for a recovering economy and an improving jobs market. The Dow Jones Industrial Average rose 0.16 percent, the S&P 500 Index climbed 0.23 percent and the Nasdaq Composite Index rose 0.74 percent.

European indices were mixed as investors remained cautious and looked for signs that stimulus measures could be on the horizon. London's FTSE 100 was down 4.56 points, Germany's DAX 30 Index fell 2.42 points and France's CAC 40 advanced 4.63 points.

Most of the Asian stock markets were up as investors seemed confident that European policymakers will make bold decisions to boost economic growth soon.