A decision was made here today during the International Olympic Committee (IOC) Executive Board meeting.

It followed a report by Namibia's Frankie Fredericks, the chair of the IOC Evaluation Commission, during which he expressed satisfaction with all four cities.

Strengths and weaknesses of each one were raised, IOC Presidential spokesperson Mark Adams without afterwards but without elaborating.

But "no significant issues were flagged that would result in a city not being advanced".

It followed four days of meetings of an Evaluation Commission Working Group last month in order to analyse responses to questionnaires given by the four contenders. 

Feedback is now set to be given via video conference later this month in order to "enable the cities to course-correct their respective projects should they so wish". 

This forms the final part of the first stage of the IOC's reformed bidding process, entitled "Vision, Games Concept and Strategy" which was introduced for the first time this cycle as part of their Agenda 2020 reforms.

The Working Group did reserve the right to recommend that a city "defers its candidature to a later campaign".

Each of the bidding cities have challenges at this stage.

Paris' foremost concern relates to security following last year's deadly terrorist attack, while Rome is seeking to retain political support ahead of Mayoral elections shortly on June 5.

Leading candidate Virginia Raggi of the populist Five Star Movement claimed the Italian capital should postpone its bid due to chronic financial and infrastructure problems.

Los Angeles, whose bid is boosted by a privately funded venue plan and strong public support, still face concerns over anti-American sentiments within the IOC as well as the possibility that Republican front-runner Donald Trump - who is hugely unpopular in much of the rest of the world - could be elected President later this year.

Budapest, the only contender to have never hosted an Olympics before, will be seeking to improve the publicity of a bid that has so far proved the lowest profile of the four. 

All four now progress to the second, "Governance, Legal and Venue Funding" stage of the process ahead of the submission of the second part of their Candidature Files on October 7. 

This will be followed by a third stage on Games Delivery, Experience and Venue Legacy.

A final choice will be made at the 2017 IOC Session in Lima.