Brussels, Sep 18 (Xinhua) NATO Secretary General Anders Fogh Rasmussen Friday called for a new beginning in NATO-Russia relations and conducting a joint review of new security challenges.

'A time-out may have been useful to rethink our relationship. But the international security environment does not wait for NATO and Russia to sort out their act. Quite simply, NATO-Russia cooperation is not a matter of choice, it is a matter of necessity,' said Rasmussen in a speech at the Carnegie Endowment in Brussels.

'This new relationship will require a lot of hard work. But if we manage to get away from the reflex of assuming the worst about each other, and focus instead on our common interests, then we can make a genuine new beginning in our relationship -- in our own interest and that of the entire international community,' he said.

This was the first public speech by Rasmussen since he took office Aug 1.

Rasmussen made the speech after an announcement by the US that the country was dropping plans to build a missile defence shield in Poland and the Czech Republic.