Reducing immigration too fast would be a mistake for the British economy, Home Secretary Amber Rudd has said.
She told the BBC she was "comfortable" with the government's target of getting net migration below 100,000, as it provided a "direction" for policy.
But she said she would not "put a date" on when the target, first proposed by David Cameron in 2009 and later adopted by Theresa May, would be achieved.
It must be done in a way to avoid harm to business and universities, she said.
Opinion is split within the Conservatives over its pledge to reduce net migration to "sustainable" levels, which the party has defined as the tens of thousands.
While most MPs back the target as a signal of the government's determination to manage numbers and exert control of the UK's borders as it leaves the EU, there are those who think it is arbitrary and cannot be met without damaging the economy, while others believe students should be taken out of the migration figures.
Speaking on the last day of the Conservative conference, Ms Rudd told BBC Daily Politics net migration was falling - the latest figures for 2016 saw it come down by nearly 84,000 to 248,000 - and she wanted that trend to continue.
While she was "perfectly comfortable" with the target, she said she understood and shared the concerns of business about the problems it could present.
"When you are working in government, it is very important to have a target so you know which direction you have got to drive policy," she told Daily Politics. "But I am not going to put a date on it.
"What I am saying is that we are going to continue to reduce it but in a way that protects business and universities and in a way that protects the economy."
Asked if she believed there was a threat to business from reducing immigration too fast, she said she thought "it would be a mistake to reduce it too fast".
"I have a lot of business organisations coming to me and saying 'we need people for this and we need people for that' so I am determined to do it in a way which allows them to skill-up people locally."
Net migration is the difference between people coming to the UK for more than a year, and the number of people leaving the UK for a year or more. It was last below 100,000 in 1997.