LONDON (Reuters) - Western sanctions on Russia for its attempts to annex the Ukrainian region of Crimea have so far been pathetic and European leaders must get tougher on Kremlin chief Vladimir Putin, a senior British lawmaker said on Tuesday.

The United States and the European Union have placed sanctions on some Russians and Ukrainians in response to a referendum in the Crimea region which Putin is signalling he will add to Russia.

"All that the international community has done so far is implement visa sanctions and asset freezes on 22 or 23 individuals - that is a pathetic response," Malcolm Rifkind, who chairs the British parliament's Intelligence and Security Committee, told the BBC.

Rifkind, a senior lawmaker in Prime Minister David Cameron's Conservative party, said the United States and European Union should get tougher with Putin, preferably with "very robust financial sanctions".

"Now it may be that as a result of what might happen that there will be a much tougher response including financial sanctions. If so that will be the right response," he said.

"But I hear very disturbing signs that it is unlikely there will be European consensus on that: that we might say ‘well only if Russia invades eastern Ukraine will it be necessary to go further'. That would be a shameful and very dangerous response."

(Reporting by Guy Faulconbridge, Editing by Belinda Goldsmith)