NATO Secretary General Anders Fogh Rasmussen and Ukrainian Prime Minister Arseny Yatseniuk discussed possible Western alliance support for Ukraine's defensive strength yesterday, while more of its troops were killed in fresh clashes with separatists.

Rasmussen's visit to Kiev followed a warning by the U.S.-led alliance that Moscow had amassed 20,000 troops near the border and could be planning a ground invasion of Ukraine as it makes progress against the pro-Russian rebels.

The two men discussed the possibility of a proposed NATO trust fund supporting Kiev's ability in areas including command and control, communications and cyberdefence, the government said in a statement. Provision of lethal aid to Ukraine by the U.S.-led military alliance did not appear to have been discussed. The Kiev government announced it was suspending a ceasefire with the rebels at the crash site of the Malaysian airliner shot down on July 17, after an international mission halted recovery work there for security reasons.