Jamie Roberts says being available for Wales duties was never in question when opting to join Harlequins.
The British and Irish Lion, 28, has signed a two-and-a-half year deal and is expected to join Quins from Racing Metro after the 2015 World Cup.
Roberts told BBC Radio Wales Sport that he wants to still be playing for Wales come the 2019 World Cup, so his country remains a priority.
"I made sure that was non-negotiable when moving to London," Roberts said.
"Conor was aware of that, he knows I want to continue to strive to achieve on the international stage.
"That was a no-brainer for me, making sure I had that in my contract
"Conor's been great with that, he understands that, and ultimately as a club they want to see their players striving to the highest level.
"I'd love to play for Wales until I retire from rugby, but you never look beyond your next game... there's a lot of strength in all positions across Welsh rugby at the moment.
"Welsh rugby's in a good place, the World Cup is huge and hopefully I want to play in another World Cup.
"I'm only 28 now, I'll be 29 in November and I'd love to [play in another]."
Roberts had turned down a deal to return to Cardiff Blues, where he spent six years before moving to France with Racing Metro.
The centre admitted the lure of his home region had been strong.
"It's probably been the hardest decision of my career... to come back to Cardiff would have been wonderful and I've got so many great memories of Cardiff," said Roberts, who has won 69 Wales caps and three for the Lions.
"It would have been an amazing thing to do and there's a little part of me that kind of feels like I'm letting a few people down not coming back.
"But I have to be quite selfish in that regard and do what I feel will make me most happy.
"I'm at my happiest when I'm doing new adventures, doing new things, challenging myself and certainly this move to London will do that.
"I play my best rugby when I'm at my happiest. That's the logic and I'm delighted to have signed for Quins.
"Originally I thought I'd be in Paris for three years so I didn't think I'd be making this decision now and over the last few months.
"Conor O'Shea at Harlequins got in touch, and after meeting with him and seeing the vision they have for the club - David Ellis the chief executive as well.
"The way Quins play the game is quite attractive, they play with ball in hand... which for me as a player it's going to bring the best out of me.
"Obviously I always want to keep learning and improving as a player and I think the way they play the game is going to help me improve certain aspects of my game.
"They play in south west London, which as a young fellow growing up in Cardiff I always looked on with envious eyes, always loved going to London."
As part of his plans to play his rugby in England, Roberts has also been accepted at Cambridge University to continue his medical studies.
As part of that, Roberts said he hoped to have the chance to play in the annual Varsity Match against rivals Oxford University.
"It was the perfect fit really and obviously I've applied to Cambridge as well to carry on doing my medical stuff," he added.
"It's going to be impossible to work as a doctor [while playing rugby professionally], so it's doing something else, doing something away from rugby to keep my hand in.
"It's all a bit of a grand plan which fortunately is coming to fruition."