Rescuers ready to travel to Turkey and Syria have been left feeling "sick" after being told to stand down.
Dog handlers Emma Whittle and Brian Jones were expecting to travel with a detection dog team to help after the earthquake.
The death toll currently stands at more than 7,200.
Ms Whittle and Mr Jones had hoped they would be able to help rescue survivors from the rubble with their specialist search dogs.
Mr Jones, of British International Rescue and Search Dogs (BIRSD), which is based in Penmaenmawr, Conwy county, said he felt "very sick because every little helps".
He said dogs could help pinpoint areas where people might be trapped.
"Instead of 30 yards square, it may be five yard square and we know there's a scent coming out of the rubble in that area," he explained.
"So we know we can mark that area for Serve On to come and extract the body."
Serve On are a humanitarian crisis organisation that works at home and abroad.
Mr Jones said a team had been sent out by the UK government on Monday.
He said: "I think they had four dogs with them. We asked if they needed our services, they said 'yes, thank you for offering'.
"We were then put on standby by Serve On. During the night we sat there.
"In the morning we got a notification from Serve On that they had been stood down and couldn't get into the country.
"The problem is between our government and the Syrian government. They couldn't get permission to go out there."
Ms Whittle has not worked in the aftermath of an earthquake before but was called in to help after a landslide in Malaysia.
"Time is of the essence, the sooner we get out there the better," she said.
The disaster happened when a 7.8 magnitude earthquake struck near the city of Gaziantep, Turkey, early on Monday morning.
This was followed by 7.5 magnitude tremor which had its epicentre in Elbistan in the south of the country.
On Monday, 76 rescue specialists were sent by the UK government to help with the search for survivors.
The Welsh Institute for International Affairs and Syrian Welsh Society is asking people to donate to organisations on the ground.
Mohammed Alhadj Ali, from the Syrian Welsh Society, said the situation was "catastrophic".
He said: "They need medical aid, they need shelters, help and support to get people out of rooms.
"That's the highest priority to be honest with you."
Dr Ali said friends had told him winter in Syria had been difficult.
There was no fuel for heating, he said, food was in short supply and prices were rising.
"They had airstrikes, they had the bombardments, the floods, tough winters and difficult summers," he said.
"It's been a decade of tragedy in Syria."
Wales' Social Justice Minister Jane Hutt said she had seen a message of sympathy to the Turkish ambassador.