High-ranking Indonesian ministers and officials have indicated privately that Indonesia would cooperate with a Coalition government to turn back people smuggler boats insists Julie Bishop, the foreign affairs spokeswoman and deputy Liberal leader, despite the country's ambassador claiming publicly that “no such collaboration will happen.”

“I have had a number of conversations with high-ranking Indonesian ministers and officials, as has [immigration spokesman] Scott Morrison as has [Coalition leader] Tony Abbott and I am convinced we can work in cooperation with Indonesia to achieve our policy aim,” Bishop said in a wide-ranging foreign policy interview with Guardian Australia.

“Professional diplomats are paid to present particular views but what goes on behind the scenes can be quite different – what people say privately can be different to what they say publicly," she said. "And we have had wide ranging discussions at the highest levels on this issue.”

On Friday the Indonesian ambassador to Australia, Nadjib Riphat Kesoema, said Indonesia would not accept asylum seekers from boats returned under the Coalition’s stated policy that it would turn back vessels when it is safe to do so.

“We don’t know the situation ahead of us right now, but no such collaboration will happen between Indonesia and Australia [to] bring back the people to Indonesia,” he said.

"Indonesia is a transit country and also the victim of this situation. I think it's not possible for the Coalition to say that it has to go back to Indonesia because Indonesia is not the origin country of these people," he said.

Guardian Australia’s interview with Bishop took place before Kesoema’s remarks but on Sunday the deputy Liberal leader insisted nothing the ambassador had said changed her assessment of the situation.

“I would expect the ambassador to say those things publicly,” she said.

Bishop emphasised it was not possible to reach any agreement with a foreign government from Opposition and no formal agreement with Indonesia had been reached.

In the interview, Bishop also revealed her determination to restore the Department of Foreign Affairs and Trade to the status of a “powerhouse department” and primary “driver of foreign policy”, saying it had lost influence over many years as the Department of Prime Minister and Cabinet had assumed responsibility for national security issues.

And she said the Coalition would try to lock in even partial agreements in long running free trade talks.

“The government has made no apparent advance on free trade agreements with China, South Korea or Japan. Our approach would be to get the best agreement we could without setting a standard that is just not achievable, to get the best agreement we could and use that as a starting point and then over time as the relationship developed and we established greater trust we could move into other areas.”

She said a Coalition government’s foreign policy would “use diplomacy to leverage economic benefits” and would be more focused on the Asia Pacific region.

Kesoema was a guest of Abbott to hear his budget speech in reply last month and the Coalition leader later claimed the ambassador’s presence “demonstrated the ability of an incoming Coalition government to work successfully with Indonesia to, amongst other things, stop the boats”.

In a statement on Sunday, Abbott said that 701 “illegal” boats had arrived in Australia since “Labor’s decision to dismantle the Howard government’s policies” and that this had “put our country’s security at risk.” He reiterated that he would “stop the boats.” The Coalition refers to "illegal" boats because they enter Australian waters illegally, although seeking asylum is not illegal.

Bishop said that since most of the boats carrying asylum seekers are Indonesian boats with Indonesian crews they “can be returned to their home ports”. Abbott has previously suggested he may not need consent from Jakarta to turn back boats because they were Indonesian-crewed and flagged and could be returned to an Indonesian port in "just the ordinary course of business".

Bishop said Indonesia would welcome a tougher Australian policy against people smugglers because “it is also struggling with a surge in the people smugglers trade and it is frustrated Australia is not doing enough to stop being seen as an attractive destination.”