Immigration levels may need to rise "from time to time", David Davis has said as he refused to commit to a cap on the number of EU citizens coming to the UK after Brexit.
In an indication that the vote to leave the European Union might not result in a dramatic fall in net migration, the Brexit Secretary said industries and public services dependent on migrant labour would need to be able to continue to recruit workers from overseas.
However, Mr Davis said he believed the Conservatives' target of reducing net migration to the tens of thousands could be reached as part of a "sustainable" policy.
Speaking to the BBC's Question Time ahead of the triggering of Article 50 on Wednesday, Mr Davis was asked if there would be a cap on "the number of EU nationals allowed in the UK".
He replied: "No, you see, the first issue here is to bring this back under the control of the UK Government, the UK Parliament, to bring migration under control.
"I don't think most people oppose migration, I think most people are in favour of migration so long as it's managed. The point is, it will need to be managed."
It would be for Home Secretary Amber Rudd to decide how migration would be managed, but Mr Davis added: "I cannot imagine that the policy will be anything other than that which is in the national interest. Which means that from time to time we will need more, from time to time we will need less.
"That is how it will no doubt work and that will be in everybody's interests - the migrants and the citizens of the UK."
Asked whether that would mean more migration than current levels, he said: "What it will be is whatever the Government judges to be sustainable."
Pressed on whether the target of reducing net migration to below 100,000 still applied, he said: "I think we will get there, but the simple truth is that we have to manage this properly. You have got industries dependent on migrants, you have got social welfare, the NHS, you have to make sure they can do the work."
Immigration was one of the major issues in the EU referendum, with leave campaigners claiming the "open door" to the other 27 nations was putting the country's security at risk, driving down wages and putting pressure on the health service.
- £50 billion EU divorce bill
Also on the programme, Mr Davis said the UK will refuse to hand Brussels £50 billion to pay for its divorce from the EU.
Along with the rights of EU residents in the UK, and British citizens living elsewhere in the EU, the demands for money are expected to form some of the first stumbling blocks in the negotiations.
The exit fee is meant to cover the UK's outstanding liabilities such as pensions and projects it has already pledged money to.
Mr Davis said the UK would meet its obligations - but he did not expect to see "that sort of money change hands".
However, European Commission president Jean-Claude Juncker has confirmed he expects the UK's "divorce bill" for Brexit will be around £50 billion.
- Trade deal contingency plans
Mr Davis also insisted that contingency plans are in place in case the UK fails to secure a deal on future trading arrangements with the EU but stressed a "comprehensive" agreement remained the Government's goal.
The 68-year-old also insisted that a "no deal" situation would not be as bad as critics claimed.
He dismissed EU negotiator Michel Barnier's warnings the UK would not be able to import nuclear fuel and would face queues of lorries at Dover as trade ground to a halt because of the increased bureaucracy.
- "Ambitious" aims for the negotiation strategy
The MP for Haltemprice and Howden was also challenged about his desire for a trade deal that will provide the "exact same benefits" as membership of the single market and customs union, and said he made "no apology for being ambitious about what we achieve."