After Shell announced a 44% fall in first quarter profits, which reflected challenges in the refining business, Simon Henry made clear the UK North Sea will face stiff competition for investment as Shell looks to boost returns.
Noting that Shell invests over decades, he told reporters: "That's why we like stability, we like the security that are given by robust economies, which typically tend to be larger ones."
Mr Henry noted Shell is investing around $2bn annually in the development of the giant Clair Ridge and Schiehallion fields West of Shetland, which it believes have good long term growth potential.
However, he said a group of mature assets absorbed around $1bn a year for "very limited growth potential".
The assets he classed as mature include the Shearwater, Gannet and Curlew developments off Aberdeen.
Mr Henry said Shell needed to think carefully about at what point those assets could be more valuable to another company. Shell put three North Sea assets up for sale in February.
Mr Henry said Shell's Southern North Sea and Dutch gas businesses were profitable but had limited growth potential.
He said Shell believes the UK's membership of the EU is positive for both sides. In the same way, he said, Scotland's memberships of the UK and the EU provided economic benefits to all involved.
Last month Shell's new chief executive, Ben van Beurden, said: "It would be better if Scotland stayed in the UK from a stability and predictability perspective."
Mr Henry stressed Shell does not make political decisions.
Asked if Shell had any concerns about the medium term tax implications of Scotland voting for independence, Mr Henry said the company wanted the fiscal regime to remain stable.
He indicated any unwelcome changes could jeopardise potentially big investments in areas like carbon capture and storage in Scotland.
Shell is working on plans for a CCS project at a power station at Peterhead that it says would be a world first.
Mr Henry said the project could lead to the development of a whole new industry.
Shell said it planned to divest $15bn assets in 2014 and 2015 as it looks to focus investment on big projects that will generate profits for years.
A range are under development in areas like the US and Asia.
The company issued a rare profit warning in January. Mr van Beurden, who succeeded Peter Voser in that month, said its 2013 performance was not good enough.
Yesterday he said Shell is focusing sharply on three key priorities: Better financial performance, enhanced capital efficiency and continuing strong project delivery. Profits on a current cost of supplies basis, excluding the value of changes in inventories, fell to $4.5bn in the first quarter, from $8bn in the same period last year.
Shell wrote down the value of refineries in Asia and Europe by $2.3bn citing excess refining capacity around the world.
Profits net of one-offs fell 3% to $7.3bn from $7.5bn.
Analysts were pleased Shell generated $14bn cash from its operations in the first quarter, up from $11.6bn in the same period of 2013 and $6bn in the fourth quarter of 2013.
Shell announced a first-quarter 2014 dividend of 47 cents ordinary share, up from 45 cents in the same quarter of 2013.
Royal Dutch Shell A Shares closed up 3%, £0.67, at £23.47.