Theresa May's European Union tour moves to Poland and Slovakia as she continues early talks on preparing for Brexit.
She will head further east on Thursday, following swift meetings with the leaders of Ireland, Germany, France and Italy since becoming Prime Minister.
But Mrs May's discussions with her Slovakian counterpart Robert Fico and Polish PM Beata Szydlo could prove more awkward given the desire of the two host countries to maintain free movement of labour.
Slovakia and Poland have also voiced concern about the rights of their nationals currently in the UK, an issue muddied to an extent by conflicting comments made by British ministers following the referendum.
Mrs May will visit the two countries after disclosing that preparations for Britain's "orderly departure" from the EU have begun.
She also insisted Britain wants to maintain "close" economic links following Brexit after meeting Italian PM Matteo Renzi.
Britain is not expected to trigger the process to start Brexit - via Article 50 of the Lisbon Treaty - before the end of the year.
Elsewhere, former United States trade representative Miriam Sapiro - an ally of Democratic presidential candidate Hillary Clinton - said the UK's trade relationship could be positive post-Brexit.
She told BBC Two's Newsnight: "While the whole issue is terribly complicated, it wouldn't be that hard to envision a trade agreement between the US and the UK done relatively quickly given that both economies are already fairly open, both countries take a fairly open perspective on liberalisation.
"They're not extremely protectionist, tariffs are already low, they both have a strong advantage in services."
Former Conservative foreign secretary Sir Malcolm Rifkind said he has no doubt that Britain could be in a strong position for its negotiations with the US.
But he told the same programme: "That isn't really the ultimate question at this stage because a decision has to be taken, first of all, by the British Government as to whether it wants to have some kind of customs union.
"Because if you have a customs union that means you actually have a common external tariff and neither Britain nor the EU could have separate trade deals with other third countries."
Liberal Democrat former deputy prime minister Nick Clegg also told Newsnight: "We're now moving, I feel, from the initial kind of panic, shock, surprise of the referendum decision to several weeks of almost phoney peace, almost a denial about the consequences of that decision.
"I think what we'll move to after the holiday break in September, October, November when we get to the political season resuming again is we'll get into a lot of this nitty-gritty."