Free movement of people between Britain and the European Union will end in March 2019, when Britain leaves the bloc, Prime Minister Theresa May's spokesman said on Monday.
Last week British finance minister Philip Hammond said there should be no immediate change to immigration rules when Britain leaves the bloc.
"Free movement will end in March 2019," May's spokesman told reporters, adding that the government had already set out some details including proposals on EU citizens' rights after the so-called Brexit.
"Other elements of the post-Brexit immigration system will be brought forward in due course, it would be wrong to speculate on what these might look like or to suggest that free movement will continue as it is now."
After members of May's top team have appeared to contradict each other in recent days over the government's Brexit plans, the spokesman also said the government position on Brexit remains as set out by the prime minister in January.
Details of a post-Brexit implementation period were a matter for negotiations, he added, but Britain is not seeking an "off the shelf" solution. The Financial Times reported last week that Hammond hoped for an "off the shelf" transition deal.