Ministers from the two ex-communist countries said they would be presenting a joint report on Wednesday to a meeting of UEFA officials on the state of preparations, sharply criticised earlier this year by UEFA president Michel Platini.
The countries were warned that they must speed up solving infrastructural problems and building stadiums ahead of the championship.
"We will approach 2009 as a single team and will get all cities ready for Euro 2012 in a responsible fashion," Ukrainian Deputy Prime Minister Ivan Vasyunyk told reporters on Monday after a meeting of top officials from both countries.
"Our new structure gives us reason to believe that we will form a unified team to tackle all tasks in 2009 and in staging the tournament."
Polish Sports Minister Miroslaw Drzewiecki added: "We have seen considerable progress in the relations between our two sides to do away with critical problems."
Vasyunyk said the main issue weighing down Ukrainian organisers had been resolved: increased financing to renovate the stadium in Kiev, due to host the final, and start building a facility in the western city of Lviv.
He added that work was under way to upgrade Kiev's international airport. Dilapidated and outdated transport networks are seen by observers as a weak link.
Preparations in Ukraine have been heavily criticised by UEFA and others. Officials dissolved an agency overseeing preparations and formed instead a 50-member "coordinating bureau" directly responsible to the government.
Foreign ministers of the neighbours are due to hold talks on Wednesday with Euro 2012 preparations to figure high on the agenda.
