BRUSSELS – NATO states back a U.S. call to show the alliance is prepared to defend Baltic members Estonia, Latvia and Lithuania from any attack after Russia's intervention in Georgia, an alliance spokesman said on Wednesday.

U.S. envoy Kurt Volker said in an interview published in Wednesday's Financial Times that the 26-nation Western military alliance must send signals through 'planning and exercises' that it intends to help shore up the Baltic states.

'Those countries are members of NATO; so if there is any attack on those countries, we will respond,' Volker told the paper in an interview.

'They are feeling a little rattled by seeing Russia use military force to invade a sovereign, small neighbouring country. We need to send signals to shore them up a little bit.

'We will have to make sure ... that the Article 5 commitment is realisable, not just as a political matter, but as a military matter too,' he said.

NATO's Article 5 guarantees defence of a NATO member by other members of the alliance in the event of attack.

NATO spokesman James Appathurai said the U.S. proposal was under discussion by NATO states and was expected to be a topic for NATO defence ministers when they hold a informal meeting in London on Sept. 18.

'I think he has reflected a sentiment that is more widely shared within the alliance,' Appathurai told a news briefing.

The spokesman said he was not aware of any request from the Baltic states for more visible NATO deployments, but they had sought more routine defence planning.

'There has been an exchange of views as to whether or not it is necessary to do it in a routine way or if we were faced as an alliance with a particular situation,' he said.

Appathurai said NATO had full capability to provide collective defence for its members. 'NATO clearly has the capability to do it and do it very quickly,' he said.

Latvia and its Baltic neighbours Estonia and Lithuania have been strong supporters of Georgia in its conflict with Russia. All four of the small nations are former Soviet states and the Balts particularly have a strong mistrust of Moscow.

NATO has promised Georgia eventual membership of the alliance – something that greatly angered Russia – but Tbilisi is not currently covered by the security guarantee.

Russia's intervention in Georgia has cast a pall over recent efforts by NATO and Russia to improve military ties.

NATO has said normal contacts are not possible until Moscow abides by terms of a French-brokered peace deal, and Russia has cast doubt on various joint projects between the two.

(Reporting by David Brunnstrom; Editing by Mark John)