Tymoshenko: Germany keeps up pressure on Ukraine
Germany says the EU is prepared to delay a trade agreement with Ukraine, ratcheting up the pressure over the treatment of jailed opposition leader Yulia Tymoshenko.
But Poland has warned against any boycott of Euro 2012, which Ukraine and Poland will co-host next month.
Several European leaders have already cancelled visits to Ukraine.
The Dutch government says it will boycott Euro 2012 unless Tymoshenko's treatment improves.
The warning came from the Netherlands Foreign Minister Uri Rosenthal in a BBC interview on Thursday.
The Dutch and German teams are among the football tournament's favourites.
Earlier, Ukraine's deputy prime minister said Euro 2012 was on track and Uefa - European football's governing body - had not complained.
"Uefa has made no serious criticism about Ukraine," Borys Kolesnikov told the AFP news agency.
"The tournament is ready and on 11 May we will be transferring the control of the four stadia to Uefa."
Tymoshenko, a former prime minister, was jailed last year for abuse of office, in a trial condemned by the West as politically motivated. She is now on hunger strike and has severe back pain.
Berlin has asked Ukraine to let her have medical treatment in Germany, as she has requested. Last week images emerged of her displaying bruises on her body - inflicted, she says, by prison guards.
The Ukrainian authorities dismissed her allegations and said she could be treated by Ukrainian doctors, but she refused.
She is an arch-rival of Ukraine's President Viktor Yanukovych, who beat her to the presidency in February 2010, avenging his defeat in the 2004 Orange Revolution.German pressure
German Foreign Minister Guido Westerwelle said that "with our EU partners we are unanimous that the EU Association Agreement with Ukraine cannot be ratified as long as the rule of law in Ukraine does not develop in the right direction".
German Chancellor Angela Merkel is reported to be considering boycotting Euro 2012 and on Wednesday the Austrian government said it would boycott all the matches in Ukraine.
Germany are due to play the Netherlands on 13 June in Kharkiv, the eastern city in which Tymoshenko is being held.
Poland has warned that the EU should not push Ukraine into the arms of Russia through a boycott.
Polish President Bronislaw Komorowski said the tournament "is not the property of this or that politician.
"It is a chance for the nation, Ukraine, to present itself from the best side," he told Polish state television.
"We feel that Ukraine is somewhere between a choice of integration with the Western world... or a chance to participate in a customs union proposed by Russia.
"From this point of view, Poland has well-grounded fears that it (boycotting Ukraine) might result in Ukraine choosing a political route alternative to the process of European integration."
Five European presidents - from Austria, the Czech Republic, Germany, Italy and Slovenia - have said they will not attend a Ukrainian summit of Central and East European leaders next week in Yalta.
And both European Commission President Jose Manuel Barroso and EU Justice Commissioner Viviane Reding have decided not to attend Euro 2012.