Relatives say they will try to raise the ransom money themselves
Relatives of crew members on a seized Ukrainian ship have urged Ukraine to pay a multi-million ransom to pirates holding the vessel off Somalia's coast.
The relatives held a rally in Kiev, accusing the authorities of inaction in the crisis, which began last month.
The Somali pirates earlier said they would blow up the MV Faina, which has a cargo of tanks, unless a $20m (£12m) ransom was paid by Monday night.
A pirate spokesman later said the deadline may be extended.
The pirates were reviewing the deadline following requests by the ship's owner and other officials, spokesman Sugule Ali told the Associated Press (AP) news agency on Monday.
He said they would decide whether to "modify it and, if that is not possible, to execute it".
US warships have surrounded the MV Faina and a Russian frigate is on its way to help in the operation.
The Kenya-bound ship, together with its mainly Ukrainian crew of 21 and cargo of 33 tanks, was seized on 25 September.
One member of the crew, believed to be Russian, died of a stroke shortly afterwards.
On Monday, a number of angry relatives of the ship's crew members gathered outside President Viktor Yushchenko's office in Kiev, demanding to hold urgent talks over the ransom demands.
"We will not leave until we meet the president. We will sleep on the stairs and will collect the money ourselves," Yelena Priskha, one of the protesters, was quoted as saying by AP.
However, the presidential office said Mr Yushchenko could not see the relatives immediately as he was attending a meeting.
The government in Kiev has said it is against using force to resolve the stand-off.
Piracy is rife in the busy shipping lanes near to Somalia's coast and along the Gulf of Aden, where dozens of boats have been hijacked this year.
Somalia has lacked a functioning central government since 1991 and has been afflicted by continual civil strife.