U.S. stocks index futures on Tuesday indicated a bounce from Monday's sharp decline even as Greece looks set default on a 1.5 billion euro ($1.7 billion) loan from the International Monetary Fund.
Reports in the Greek media on Tuesday that Prime Minister Alexis Tsipras is considering the latest aid proposals from the European Union helped European stocks pare some losses and boosted stock futures during London trade.
However, German Chancellor Angela Merkel played down any hopes of a last-minute deal with Greece. She said in a Reuters report that she was not aware of any new offer from the European Commission president.
Equity index futures for the three main U.S. markets held higher, with Dow Jones industrial average futures up about 90 points.
A worsening crisis in Greece sent U.S. shares tumbling 2 percent on Monday with the Dow and S&P posting their worst losses for the year. Asian markets recovered some ground on Tuesday, with Japan's Nikkei closing 0.6 percent higher.
Not only does Tuesday bring the deadline for a major IMF loan repayment, but also marks the expiration of Greece's existing bailout terms. Greece has said it will hold a public referendum on Sunday on Greece's bailout program and austerity measures.
The failure to secure a cash-for-reforms deal with its international creditors, together with the implementation of drastic capital controls, has fueled concerns that Athens is lurching closer toward a sovereign debt default and possible exit from the euro zone.
"Missing the (IMF) payment doesn't change much, what does change is that the program lapses at mid-night and that means we're back at square one," Moritz Kraemer, chief rating office at ratings agency Standard & Poor's, told CNBC.
"This would be the first time in over five years that Greece has no support program from the European Union," he said.
S&P later Monday downgraded Greece's credit rating to "CCC-" from "CCC."
U.S. economic data due this session include the June Chicago purchasing managers' index and June consumer confidence index. The data highlight of the week is the U.S. non-farm payrolls report, which will be published on Thursday.
The S&P/Case-Shiller home price index showed a 4.9 percent rise in April.
Elsewhere, U.S. Treasury yields were marginally higher, while the euro was weaker at $1.118 and the yen was slightly stronger against the dollar at 122.47 yen. The dollar gained nearly half a percent against major world currencies.
In addition to Greece, investors are eyeing Puerto Rico, where another potential debt crisis is brewing. Puerto Rico Governor Alejandro Garcia Padilla late Monday said the island needs a restructuring plan for its $72 billion in debt.