"If I don't believe it I am not staying here," the 39-year-old Portuguese head coach told reporters ahead of Saturday's FA Cup third round tie with Swansea City when asked about the club's survival prospects.
"I know many people... say that we need a miracle to remain in the Premier League, it's normal that you say this. But sometimes they happen, the miracles.
"We'll try and maybe in May the miracle will happen. We'll see," added Silva, whose contract runs only to the end of the season.
Hull are bottom of the table, two points adrift of Swansea and Sunderland, and without a win in nine league matches.
Although one caller to local BBC Radio suggested before his appointment on Thursday that Hull would have as much chance with the fictional pirate Long John Silver, the new manager has an impressive pedigree in Portugal and Greece.
He took Estoril to the Europa League, won the Portuguese Cup with Sporting Lisbon and the Greek league title with Olympiakos Piraeus.
Silva said Hull was a different challenge, described his emotions as "normal" and played down comparisons with compatriot and Manchester United manager Jose Mourinho, Chelsea's former 'Special One'.
"Mourinho is Mourinho...I describe myself as Silva. You know my name and my name is Marco Silva," he said.
"I am Marco Silva only."
He said Hull clearly needed to do deals in the transfer window but he had confidence in the existing squad and had worked with 13 of the players already on Thursday.
"The owners know, I know what we need, but I will only speak about these players when they sign with the club," added the manager.
"We’ll try to find solutions to try and improve the team. Of course I have targets, but it’s not the moment to talk about this."
(Reporting by Alan Baldwin, editing by Toby Davis)
