Some executions in the US are being delayed because of a nationwide shortage of sodium thiopental, one of the drugs used in lethal injections.
Several of the 35 states that use lethal injections are now hunting for fresh sources of the drug, which is used to render people unconscious.
The sole US manufacturer of the drug says new batches of sodium thiopental will not be ready before early 2011.
Meanwhile, nine states have planned 17 executions before the end of January.
Manufacturer Hospira has blamed the shortage of the drug on unspecified problems with its raw-material suppliers.
"We are working to get it back onto the market for our customers as soon as possible," Hospira spokesman Dan Rosenberg said.
Hospira has previously made clear that it is not comfortable with its products being used in the lethal injection process.
Officials in California are pressing for its first execution in over four years to go ahead on Thursday evening as scheduled, because the state's last remaining batch of sodium thiopental expires on Friday.
Any other executions would have to be delayed until a new batch of the drug is received by the state next year.
Oklahoma delayed a planned execution last month because of the sodium thiopental shortage. A lack of the drug also led Kentucky's governor to put death warrants for two inmates on hold.
Sodium thiopental is primarily used as anaesthesia for surgical patients and to induce medical comas. It has also been used to euthanise animals.