The number of migrants waiting for their asylum claims to be processed in the UK is "unacceptably high", an internal Home Office document seen by BBC News says.
Asylum registration should be completed in 10 days but the leaked report says it is taking 17.
The delays could leave the Home Office "open to criticism or possible legal challenge", it says.
The Home Office said it did not comment on leaked documents.
The report also said that in the last three months of 2018, applications for asylum hit their highest level since the European migrant crisis in October 2015.
This was more than 20% higher than the Home Office office expected.
However, it said asylum applications in the UK had remained broadly stable in the 18 months up until that point.
The report, dated January 2019, also highlighted the pressure being felt in Kent due to boats carrying migrants arriving on the coast.
But the Home Office told the BBC these made up only a very small proportion of the total number of asylum claims.
According to the document, there is now a backlog of claims waiting to be processed which is "unacceptably high".
It says the delays are "unfair on those who have claimants who need us to process a significant event in their lives".
It also said the delays could cause "reputational damage to the Home Office".
How many asylum seekers are there in the UK?
In 2017, there were 26,350 asylum applications made in the UK.
This compared with 198,255 applications made in Germany, 126,550 in Italy and 91,070 in France.
In the UK, 31.8% of 21,290 decisions awarded some protection to the asylum seeker.
Before an asylum claim can be registered, the Home Office has to interview the asylum seeker to establish their personal details.
At the interview, officials will also find out about any vulnerabilities the person might have and whether they need accommodation or financial support while their claim is being processed.
The document sets out a plan for recovering from the backlog at three immigration centres across the country - known as asylum intake units.
These centres - in Kent, Bedfordshire and Croydon, south London - conducted around 78% of interviews with asylum seekers in the UK from April 2016 to March 2017.
How does someone seek asylum?
If someone wishes to stay in the UK as a refugee, they must be unable to go back to their country because of a fear of persecution, the government says.
They should apply for asylum when they arrive in the UK or as soon as they realise it would be unsafe to return to their home country.
After they have made an application, they will go to a "screening" - a meeting with an immigration officer - where they will be asked why they want asylum.
Following that, they will undergo an interview during which they are asked to explain and show evidence of how they were persecuted in their home country and why they are afraid to go back.
A decision will usually be made within six months, the government says.