Earlier on Tuesday, the Ukrainian parliament passed a bill cancelling the country's non-aligned status and confirming Ukraine's intention to join NATO.
"It would be necessary for Ukraine to achieve the standards expected of an Ally and be able to undertake the commitments and obligations of membership before being invited to join the Alliance. We continue to recognise the Distinctive Partnership that NATO shares with Ukraine through the NATO-Ukraine Commission and value their contributions to Alliance operations," the source said.
The source added that the United Kingdom continued to support the "open door" policy, according to which a country should decide on its own whether to pursue NATO membership or not.
"The decision over whether to seek NATO membership is a matter for the people of Ukraine," the source said.
However, the new Kiev authorities have renewed the drive toward NATO membership since an armed conflict broke out in southeastern Ukraine. Russian Foreign Minister Sergei Lavrov has repeatedly warned Kiev that a non-aligned status is in the best interests of the Ukrainian people, their neighbors and Europe.
Ukraine's NATO bid has prompted a mixed reaction from the alliance, with the majority of NATO officials saying the country was not ready to join the bloc and urging Kiev to implement a wide range of reforms before pursuing membership.
