* West should not rule out sending weapons, commander says
* Islamic State call a response to pressure: Breedlove  

Reuters/Brussels

The West should consider using all its tools to help Ukraine, including sending defensive weapons, NATO's top military commander said on Sunday.

Officials in Washington have been discussing whether to send weapons to Ukraine's military to help them fight pro-Russian separatists who NATO says are armed and supported by Moscow.

"I do not think that any tool of U.S. or any other nation's power should necessarily be off the table," U.S. Air Force General Philip Breedlove told a Brussels conference when asked if he was in favour of sending defensive weapons to Ukraine.

The West imposed economic sanctions on Russia over its role in the conflict in eastern Ukraine and its annexation of Crimea last year, but fighting has continued.

Without naming Russia, Breedlove said diplomatic, information, military and economic tactics were all being used against Ukraine.

"And so we, I think, in the West should consider all of our tools in reply. Could it be destabilising? The answer is yes. Also, inaction could be destabilising," Breedlove said.

He said NATO intelligence pointed to "disturbing" military developments in eastern Ukraine and voiced concern about whether a ceasefire deal reached in Minsk last month was being complied with.

"We continue to see disturbing elements of air defence, command and control, resupply, equipment coming across a completely porous border," he said at the Brussels Forum, organised by the German Marshall Fund thinktank.

Asked about reports that Russia's ambassador to Denmark had warned that Danish warships could become targets for Russian nuclear missiles if Denmark contributed to a NATO missile shield in Europe, Breedlove said this was the "next step" in a campaign against countries that joined the shield.

"Romania came under great pressure when they became a part of the (missile shield). Poland is coming under great pressure and now anyone else who wants to join in to this defensive capability will come under this diplomatic and political pressure," Breedlove said, again without naming Russia.

The shield was intended to defend Europe from a potential missile threat from Iran. Moscow says the system will undermine Russia's nuclear deterrent because it could also enable the West to shoot down Russian missiles.

Breedlove, who is also commander of U.S. European Command, said a call by Islamic State, the Islamist militant group fighting in Iraq and Syria, for supporters to kill 100 U.S. military service members whose addresses it posted online was "just one more of their sensational tools".

"This caliphate, I think, is under great pressure and so they try to divert attention from what is happening on the battlefield by putting out one of these great splashes," he said.