The Prime Minister has travelled to Warsaw for an annual summit designed to strengthen the relationship between the UK and Poland as Britain prepares to leave the EU.
As part of the summit, Theresa May is expected to announce a new joint UK-Poland Treaty on Defence and Security Co-operation.
The only other European Union country to have such a treaty with the UK thus far is France.
The UK will provide £5 million for the project, with Poland expected to contribute a similar amount.
It is hoped that the treaty will provide a framework for co-operation on training, exercises, information sharing, defence industry co-operation and defence development capability.
The British deployment of troops to Poland will also be built upon.
The aim of the project is to allow both Britain and Poland to detect and counter Russian information operations.
Speaking ahead of the summit, the Prime Minister said:
“Poland matters greatly to the UK: our partnership is broad, vibrant and diverse and we both share a steadfast commitment to Europe’s security and defence.
“I am determined that Brexit will not weaken our relationship with Poland. Rather, it will serve as a catalyst to strengthen it.
“And that is why I am in Warsaw today, to ensure that we can work even more closely together to ensure the security and prosperity of our nations in the years ahead.
“Although the UK is leaving the European Union, we are not leaving Europe. And I will reaffirm to Prime Minister Morawiecki that we want to work with Poland and the other member states in the future to protect our shared values, people and interests.
“We are building a strategic partnership from a base of shared history and deep ties of friendship that will continue to flourish long after our departure from the EU.
“The bilateral defence treaty we are signing today is a powerful symbol of our continued close cooperation.”