The "entire machinery of government" is focused on getting the Brexit deal, Patel said on BBC's Andrew Marr Show, but declined to reveal details, saying it wasn't "a public negotiation".
Stating almost 10 times that the government was aiming for a deal to leave the EU, and not mentioning once the possibility of leaving without one, Patel also stressed that a condition of her becoming a minister was a government's serious attempt to get a deal.
"When he (Johnson) brought me into government, along with other colleagues, we were clear to him, as he was to us, that our focus is on leaving on October 31 with a deal.
"Our job right now is to absolutely give confidence to securing that deal, and backing the Prime Minister in everything he is doing to secure that deal through the negotiations that are currently under way," she said in the interview.
Patel's statement came even as Johnson said the UK would break out of its "manacles" like 'The Incredible Hulk' in order to leave the EU, media reports said on Sunday.
He had said on Friday that he was "cautiously optimistic" of getting a Brexit deal, but the UK would leave by the deadline "whatever happens", despite MPs passing a new law that would force the Prime Minister to ask the EU for an extension to that deadline if a deal wasn't agreed by October 19.
Patel, however, maintained that Johnson is "fully committed" to getting a deal.
"I hope the country has heard (Johnson's) sheer commitment and determination to ensure that we leave on October 31, and also that the entire machinery of government now is focused on getting that deal and is planning and preparing to leave with a deal.
"My instinct is we have to leave, and we have to leave with a deal on October 31," she said.
( With inputs from IANS )