KIEV (AFP) - Nato chief Anders Fogh Rasmussen on Thursday vowed support for Ukraine in the face of Russian "aggression" and called on Moscow to withdraw its troops from the border.

"Nato ... stands ready to support Ukraine" with advisors and other assistance, Mr Rasmussen told journalists during a visit to Kiev.

He also said the downing of Malaysia Airlines plane was a result of Russia's "reckless" support to Ukraine separatists.

Mr Rasmussen was speaking after Nato said Wednesday that Russia had amassed 20,000 troops near the border and could be planning a ground invasion of its neighbour. Russia "should not use peace-keeping as an excuse for war-making," he said.

"I urge Russia to follow the general path to peace, to pull back troops from the border," he said.

(More to come)