Ministers remain "absolutely" committed to reducing net migration to the tens of thousands, Downing Street insisted.
Number 10 acknowledged that it would "take time" to reach the goal but the target remained in place.
Theresa May's spokesman reiterated the commitment after Home Secretary Sajid Javid gave only lukewarm support for the target.
Asked if he was "personally committed" to the goal Mr Javid told the BBC's Andrew Marr Show "I'm committed to our manifesto".
The Prime Minister's official spokesman said "we have always said this is a process that will take time" but "net migration is falling".
"It is a long-standing manifesto commitment," the spokesman said.
"I think the public are clear that they do want migration reducing to sustainable levels."
The spokesman also said that visa routes are "always under review" amid concerns about the ability of the NHS to recruit foreign doctors under the current monthly quota system for tier 2 visas.
"Currently around one third of all tier 2 places go to the NHS and there are now record numbers working in the NHS," the spokesman said.
"Visa routes are always under review and we are monitoring the situation in relation to visa applications for doctors including the monthly limits through the tier 2 visa route."
Mr Javid acknowledged there was a "perception problem" about including students in the overall net migration figure, but Downing Street insisted there would not be a change in policy.
Mrs May, a former home secretary, has always resisted removing students from the figures.
Her official spokesman said: "The Government is absolutely clear that international students are greatly valued by the UK and we remain committed to ensuring our top universities are a magnet for talented students from around the world.
"We have been very clear that there is no limit on the number of genuine students that can come to study here but we need to be able to plan for the services they need so it is important we have a full picture of who is arriving and who is leaving."
DIANE ABBOTT CRITICISES 'INHUMANE' FAMILY REUNION RULES
Refugee family reunion rules are "inhumane" and in breach of human rights, the shadow home secretary has claimed.
Diane Abbott said the current rules "break up families" as she urged the Government to review them.
During Home Office questions in the Commons, Ms Abbott told Sajid Javid: "The importance of family life ought to be something that unites both sides of the House, but the current rules break up families - many of us see it in our own constituency caseloads, week after week.
"The current rules are inhumane and in breach of the right to a family life under Article 8 of the European Convention on Human Rights.
"It's also unfortunate that legal aid for some of these applications was previously available but was removed under the coalition in 2013."
She went on to ask: "Surely the Home Secretary should move faster to reviewing his current family reunion rules?"
The Home Secretary said 25,000 people have been reunited over the last five years, a figure he said was "not an insignificant number".
He added: "She says the current rules are inhumane: it's worth reminding her that they were introduced in 2007 by the previous Labour government, so perhaps she should reflect on that.
"And she talks about legal aid and she will know that it is under review by the Ministry of Justice as something we're looking at carefully."
Earlier in the question session, Mr Javid said the Government was looking at Private Members' Bills which seek to address the issue.
It came after Labour's Jo Stevens (Cardiff Central) told MPs: "Whilst adults can sponsor their relatives, under the UK rules separated children have no family reunion rights - not even to bring their parents to the UK.
"Every other country in the EU allows children to sponsor at least their closest relatives - when will the UK do the same?"
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