Benefit claimants who have suffered problems because of a welfare overhaul have been given an apology by a UK government minister.
Universal credit merges six benefits into one monthly payment but critics said people have had to wait six weeks for their first payment.
Work and Pensions Minister Damian Hinds told BBC Wales the change was helping people back into work as intended despite "mistakes" in its introduction.
He said the wait had also been cut.
Critics have complained about people being pushed into financial difficulty while they wait for money.
After mounting opposition, Chancellor Philip Hammond announced changes in the Budget, including cutting the waiting time for a first payment from six to five weeks.
With food banks linking rising demand to problems with universal credit, Mr Hinds said advance payments were available to tide people over.
"As I say, when mistakes get made, and that does happen I'm afraid in benefits systems, I'm sorry for that," he added.
"There were times when there were delays in the first payment and again that's something which I'm sorry for, but we have improved."
He said advance payments were also now available.
'Challenges and issues'
Universal credit is being introduced across the UK in stages, with the whole of Wales due to be covered by November 2018.
By mid December, more than 26,000 people in Wales had joined the system.
In April, Flintshire became the first part of Wales where all benefit claimants were switched to universal credit.
The local council says it has presented a "significant number of challenges and issues", including tenants falling behind with the rent.
Salli Edwards, chief executive of Flintshire Citizens' Advice, called for the roll-out to be paused so staff at the Department for Work and Pensions could have more training.
Some claimants had been given the wrong advice when they applied, she said.
Ms Edwards welcomed the changes announced in the chancellor's budget, but said they were "tweaks" which were "not actually going to resolve the issues for a lot of claimants at the moment".
"And they are certainly not going to remove the poverty that we are seeing people in," she added.
Labour's Lord Hain, who served as Work and Pensions Secretary under Gordon Brown, said: "I have sympathy with any minister of whatever party trying to grapple with this incredibly complex, enormous, £150bn budget system.
"But I do not have any sympathy if you're trying to slash that budget at the same time because you cannot get a quart into a pint pot - and that's what they've been trying to do."