Belfast Briefing: "Hello corporate America - we're open for business." That's the all-important message Ian Paisley and Martin McGuinness are out to promote this week in the United States.

The North's First Minister and his deputy are on a week-long mission to change the hearts and minds of Americans - particularly those making investment decisions.

Americans know about the peace process of course but, for decades, the only image they had of the North was one of violence and hatred. No press release promoting the real investment opportunities which now exist in Northern Ireland can compete against the residual image of teenagers throwing petrol bombs.

Dr Paisley and Mr McGuinness hope their first trip to the US together will leave a new lasting impression on the hearts of those in charge of deciding where investment dollars go. They are planning an all-out charm offensive to show America that Northern Ireland really has changed.

People at home still find it hard to believe that a former IRA commander and his most bitter critic can do business together, so if corporate America still has doubts, nobody would be surprised.

What the duo need to do is convince America's decision-makers that two previously bitter enemies can bury their hatred and distrust of each other.

In order to do this the First and Deputy Ministers plan to hold meetings in New York with mayor Michael Bloomberg and dozens of high-profile corporate chiefs and Wall Street bosses.

To finish off their US tour, they will then fly to Washington for the ultimate photo opportunity with president George Bush.

During the trip they are going to issue what Mr McGuinness has described as "an open invitation" to US businesses to come and see at first hand what Northern Ireland can offer.

Yesterday they met Mr Bloomberg. Dr Paisley said he believed Northern Ireland could learn lessons from how the city had tackled some of its problems.

Speaking in New York, Dr Paisley said: "The deputy First Minister and I have invited Mayor Bloomberg to lead a business delegation to Northern Ireland in the near future which we hope will continue our already strong economic relationship with the US."

The ministers' first objective will be to get companies to sign up to a major US/Northern Ireland investment conference which is scheduled to take place in Belfast next spring.

It will be no easy task persuading US corporate chiefs to consider the North as an investment location in the current economic climate. But perhaps if politicians in the North can persuade the likes of the US billionaire Donald Trump that it is a viable option, then it might get the ball rolling.

Trump wanted to develop a £1 billion golf and housing complex in Aberdeenshire in Scotland, but the local council rejected his proposals on environmental grounds. The Rev Robert Coulter, the Ulster Unionist North Antrim assembly member, believes the North would be an ideal location for this kind of development.

Overtures have been made to the Trump organisation and, according to George Sorial, it is now "looking seriously" at Northern Ireland as an option.

There is no debate in the North about how important it is to secure new inward investment to create desperately needed jobs, and America is top of the wish list.

Invest Northern Ireland has supported 50 US investment projects since 2002 which have either safeguarded or created more than 10,000 jobs. The value of these projects to the local economy is worth an estimated £570 million.

The Deputy First Minister has stressed that the Northern Ireland government has put the economy at the top of its priorities and will do all it can to support businesses.

According to Michael Smyth, senior lecturer in Economics at the University of Ulster, there has rarely been a better set of "pro-business policies" in place. In the First Trust Economic Outlook and Business Review, he says the North's budget sets the right direction for the economy.

Mr Smyth believes the key to the North's long-term economic success lies in encouraging greater private sector investment. That's why Dr Paisley and Mr McGuinness are not only engaged in a public relations exercise in the US, but on a credibility mission. They have got to convince corporate America that it can put its investment dollars safely and securely in Northern Ireland.

There will be difficult questions to answer over concerns that the North will not go back to its bad old ways - or that Dr Paisley will not wake up one day and remember why he did not like Martin McGuinness in the first place.

This US trip is all about the "seeing is believing" factor and tomorrow the North ministers will make their most important gesture yet in America. The pair is due to formally open trading on Nasdaq by signing the electronic screen and pressing a button as they do this their image will flash up on Nasdaq's giant screen in the heart of Times Square.

If that does not convince corporate America that there is no going back this time for Northern Ireland, nothing will.