The pair arrived at Belfast International Airport on Thursday after their 12-day trip, where they visited Sao Paulo and Rio de Janeiro in Brazil, Los Angeles and Washington in the USA.

The deputy First Minister hit back at claims the mission was a five-star trip at the expense of the taxpayer.

"It was a very important visit, we took a decision some time ago at the foot of the huge success we've had in attracting new inward investment from the USA, that it was important to go out to countries like China, India and Brazil and I think people need to understand that if you don't go out to these places you don't count," Mr McGuinness said.

"Unless you are in a position to build up personal relationships, with people in the trade business community and in the government, then effectively we're shutting down the prospects of increasing trade and increasing jobs in our own country."

Mr Robinson added: "In terms of the worth of the visit, we can close down the doors, we can pull the shutters down, we can have a little northerner attitude, or we can reach out to the rest of the world and try and capture jobs, bring investment to Northern Ireland and try and bring visitors here as well."

Mr McGuinness also refuted claims of secrecy regarding the trip, saying he updated details everyday on social networking site Twitter.

Great to be back on Irish soil,tired. Trade missions as our US successes prove are Vital.China-Brazil-New Relationships Vital.No go-No count

— Martin McGuinness (@M_McGuinness_SF) March 21, 2013

On Thursday he tweeted: "Trade Missions to US which produced thousands of new jobs NOT one journalist from here went. Only 2 at airp't this morn!"

"Taxpayers understand that government ministers, if they're to have any hope whatsoever of increasing jobs, have to go to these very very important countries, which are powerhouse economies," he told UTV.

"Like the visit that we had to Brazil, for example, we met political leaders of the highest level.

"And of course the trip to Los Angeles was hugely important given the success of the Game of Thrones and the pitch that we've made to have the fourth series made in the north of Ireland. So I don't have any difficulty whatsoever in justifying the effort that we made."

Mr McGuinness added that he was a "homebird" and that the ministers were making personal sacrifices being away from their families.

The First and Deputy First Ministers will travel to Downing Street on Tuesday to hear Prime Minister David Cameron's response to their campaign for devolved corporation tax.

"We've brought forward a report, that shows that it can be done," Mr Robinson explained.

"(Former NI secretary) Owen Patterson, advocated it at the time and went as a trailblazer for it, so that's what we're expecting the Prime Minister to be dealing with.

"Obviously from a Northern Ireland point of view, that's the best option for us."

The pair answered questions side-by-side at the airport, with both the ministers denying reports their relationship was "frosty".

"Peter and I have a good working relationship," the deputy First Minister said.

"We've been in government together for six years, without interruption. There's never been an occasion where we haven't spoken to each other, the institution has never collapsed so I think that's a big success."

Mr Robinson and Mr McGuinness also undertook a six-day business mission to China in November last year.

Worthwhile & positive engagement in LA with leaders from financial & legal services, ICT & film industry. Hosted by UK Consul General & INI.

— Peter Robinson (@DUPleader) March 16, 2013