Polish Prime Minister Donald Tusk and Czech Prime Minister Bohuslav Sobotka met in Prague on Thursday to discuss regional security and energy issues. The two leaders talked about the situation in Ukraine and the need to ensure stability in the region. They also discussed the importance of energy security and the need to diversify energy sources. The two leaders agreed to cooperate on energy projects, including the construction of the Nord Stream 2 pipeline, which will transport Russian gas to Europe. They also pledged to cooperate on the development of renewable energy sources. The two countries also agreed to cooperate on strengthening border security and combating organized crime.