A lack of marketing could mean Wales misses out on economic opportunities surrounding the Nato summit, officials from the host resort have warned.
Bosses of the Celtic Manor in Newport criticised a lack of a marketing campaign by the Welsh government when they appeared before a committee of MPs.
They also said it was "shameful" they had closer links with Bristol Airport than Cardiff due to the Welsh airport offering fewer routes.
The summit is held in September.
With little more than 100 days to go before up to 60 world leaders arrive at Newport's Celtic Manor Resort, its chief operating officer told MPs that nothing had been "nailed down" in terms of a planned outreach programme.
Ian Edwards said it was "shameful" that the resort worked more closely with Bristol Airport on an international campaign because it offered more routes than Cardiff Airport.
He said Wales had done well out of the Ryder Cup at the resort, but could have done better.
'Back of the queue'
"We've got to learn the lesson from the Ryder Cup and make sure we don't make the same mistakes with Nato," he said.
Mr Edwards told MPs on the Welsh affairs committee: "At the moment it's more viable for us to have an alliance with Bristol Airport to put on an international campaign because they have more routes coming into Bristol than into Cardiff.
"How shameful is that?"
The Nato summit will be five times the size of the Ryder Cup, with delegates and media staying in hotels from Swansea to Swindon.
Mr Edwards said no-one in the Welsh government was promoting the conference market, where delegates spent three times as much as ordinary leisure visitors.
The resort's director Simon Gibson said that before the Ryder Cup people overseas thought Wales was spelled "whales".
The executives criticised the "GREAT Britain" marketing campaign to bring tourists to Britain.
Mr Edwards said: "We only became part of that because of the Nato summit. Before that, it didn't exist."
Under new management
But Mr Edwards also told MPs that he believed that the body promoting Welsh tourism - Visit Wales, was effectively under new management.
"Visit Wales is under a new leadership, new direction, and is still sort of finding its feet at the moment," he said.
"Once everything is pulled together, we will have the right team to move things forward."
He told the MPs that he felt the Welsh government was working hard towards ensuring the Nato event was a success.
He added: "We will absolutely be ready for Nato. We have to be ready for Nato - it's not an option."
However, Mr Gibson went on to criticise UKTI, the government department charged with helping business, for inviting Wales to take part in investment opportunities late in the bidding process for a share of investment from sovereign wealth funds.
"I don't always think we're at the front of the queue at UKTI when it comes to opportunities," he said.
'Maximising Nato benefits'
"It's billions. An opportunity like that might have paid for the M4 relief road.
"It could have done all sorts of projects of a large nature but if we're at the back of the queue we're going to lose."
Responding to some of Mr Edwards comments, a spokesperson for the Welsh government said: "We have an excellent relationship with the Celtic Manor and are working closely with them and the UK Government to ensure we maximise the benefits to Wales from hosting the NATO conference.
"We are also working closely with the Celtic Manor on plans to deliver a world-class convention centre to enhance Wales' reputation as an international destination for major conferences."