"We have stopped trying -- we said everything we needed to his manager and friend ... but we haven't heard anything back," the administrative director of the Swedish Academy Odd Zschiedrich told CNN on Tuesday.
"We will have the ceremony as usual, he will have the prize even if he is not there...now we are just waiting for information," he added.
"Right now we are doing nothing. I have called and sent e-mails to his closest collaborator and received very friendly replies," said Sara Danius, Permanent Secretary of the Swedish Academy on Monday, Xinhua news agency reported.
On October 13, the very day that Dylan was announced the winner of the prize for "having created new poetic expressions within the great American song tradition", he gave a concert in Las Vegas but did not speak a word about the award.
When Dylan performed on the next day in the US city of Coachella, once again he failed to mention the prize, although another band on the same stage congratulated Dylan on winning the award and spoke highly of his achievements.
Dylan's silence about the Nobel Prize puts a question mark on his appearance at the award ceremony in Sweden scheduled in December.
However, Danius said she is not worried. "If he doesn't want to come, he won't come. It will be a big party in any case and the honour belongs to him."
But "I think he will show up," Danius added.
Bob Dylan was born on May 24, 1941 in Minnesota, US.
On May 29, 2012, at the White House in Washington D.C., US President Barack Obama, who called himself a fan, presented Dylan with the Presidential Medal of Freedom, which is one of the nation's highest civilian honours.