Image copyright Martyn Jenkins Image caption One of Wales' stunning coastal attractions - Three Cliffs Bay on Gower

The drive time between north and south Wales is a "barrier" to increasing international tourism, according to a UK travel trade body.

UKinbound estimates Wales attracts one million foreign tourists a year, spending an estimated £330m annually.

Chief executive Deirdre Wells said more could be done to improve south to north links, which is currently a four-hour drive.

The Welsh Government said it was investing in the road and rail network.

Speaking at UKinbound's conference in Cardiff, chief executive Deirdre Wells told BBC Wales they had brought the event to the city to help encourage tour operators to sell Welsh holidays to their foreign customers.

The founder of Zip World in Snowdonia, Sean Taylor, told the conference about the difficulties of travelling from north to south Wales. Asked to respond, Ms Wells told BBC Wales she agreed that the four-hour drive was a barrier to tourism.

"I think we can be doing more to make these transport links as good as they possibly can be," she said.

"We do have a default setting on promoting commuter lines but actually the leisure business [does] a huge amount to bolster the sustainability of transport."

She said that the reliance on east to west road connections makes the entry points to Wales particularly important.

"There are some fantastic new routes into Cardiff [airport] and that always helps when you have the ability to fly people into the destination directly," she added.

Image copyright Getty Images Image caption Picture-postcard lovely - Tenby in Pembrokeshire

Caerphilly Castle, St Fagans Museum and Folly Farm are among the most popular tourist attractions in the south while Snowdon, Conwy Castle and the Italianate village of Portmeirion are well-visited in the north.

The A470, which is largely a single-carriageway road between Cardiff and Llandudno, is the most frequent route for travellers between Wales' two most populated coastal areas.

Image copyright Getty Images Image caption Pontcysyllte Aqueduct near Llangollen is a World Heritage Site

Image copyright Getty Images Image caption The A55 road along the north Wales coast is the main route from the port of Holyhead to England

The Welsh Government said it is marketing three road trip routes to tourists to showcase Wales.

An official added: "This is… alongside the investment we continue to see across our trunk road network, the procurement of an improved rail service and our ongoing offer of free weekend bus travel across the TrawsCymru bus network."