The U.N.-Arab League envoy on Syria, Kofi Annan, said on Wednesday he expected to visit Syria fairly soon and made a plea for Syrian President Bashar al-Assad to engage with efforts to end the country's bloodiest turmoil in decades.

The outside world has proved powerless to halt the killing in Syria, where repression of initially peaceful protests has spawned an armed insurrection. Russia and China have twice used their vetoes to block any action by the U.N. Security Council.

I would plead with (Assad) that he should engage, not only with me, but with the process we are launching, Annan told reporters after meeting with U.N. Secretary-General Ban Ki-moon in New York. I would expect to get to Syria fairly soon.

The first thing we need to do ... is everything we can to stop the violence and the killing, to facilitate humanitarian access and to ensure that the needy are looked after, and work with the Syrians in coming up with a peaceful solution, said Annan, who was U.N. Secretary-General from 1997 through 2006.

Annan described his role as a very difficult assignment, it's a tough challenge and also appealed for the international community to act as one in attempting to end the fighting.

I strongly urge the Syrian authorities to extend their full cooperation, Ban told reporters on Wednesday after his meeting with Annan. I call on them once again to work towards a peaceful democratic solution for the Syrian people.

U.N. Under-Secretary-General for political affairs Lynn Pascoe told the U.N. Security Council on Tuesday that well over 7,500 people have been killed in Syria during an 11-month government crackdown on pro-democracy protesters.

(Reporting by Michelle Nichols; Editing by Paul Simao)