The head of Human Rights Watch on Tuesday praised a hardening of German Chancellor Angela Merkel's stance on Russia and urged her to also take a tougher line in upcoming talks with China.

Merkel met the chief of the New York-based rights watchdog, Kenneth Roth, and Amnesty International secretary general Salil Shetty at her office in Berlin on issues including the Ukraine crisis and a visit to Germany this month by Chinese President Xi Jinping.

Roth told AFP that striking the right balance between business interests and policy principles had dominated the discussion.

"We all recall 'Ostpolitik', the thinking that if you just engage with Russia then everything will gradually get better," Roth said after the 45-minute meeting.

"That view is now widely discredited so the chancellor and Foreign Minister (Frank-Walter) Steinmeier are in the process of rejiggering their Russia policy and we're seeing that under way."

Merkel, as the European Union's most influential political leader at the helm of its biggest economy, faced criticism early in the Ukraine debate for doing too little to rein in Russian President Vladimir Putin due to post-war diplomatic tradition and German reliance on Russian energy and imports.

Roth said Merkel now seemed ready to bring pressure to bear against Putin in a language he understood.

"Certainly the rhetoric has been tougher, the beginnings of sanctions are being imposed and there seems to be a much more clear-eyed understanding that Putin is not going to respond to engagement per se (which he sees as) a sign of acquiescence and weakness and that the only thing that works with Putin is toughness," he said.

Roth said he and Shetty had urged Merkel to get at the root of Putin's "adventurism" in Ukraine's Crimean peninsula.

He said this included deploying international monitors and leaning on the new government in Ukraine to ensure the rights of the Russian-speaking minority in Ukraine are protected -- moves Merkel has backed. Putin has cited rights violations to justify the seizure of Crimea.

But Roth said the bigger issue which had largely been ignored in the West was that Putin's stifling of dissent at home had laid the foundations for the current turmoil.

"The origins of what makes it possible for Putin to do what he's doing in Crimea and what he's threatening to do in the rest of eastern Ukraine are the crackdown on civil society and the suppression of the media in Russia" which offer a "one-dimensional, propagandistic view" of Putin's policies, Roth said.

- 'Call their bluff' -

He said that if the West continues to deploy more of its "arsenal" of biting sanctions, the "economic pain" would force Putin to recalculate.

Similarly, Roth said, Merkel should not be afraid to challenge Xi on human rights during their upcoming talks.

"Despite what Beijing would like you to believe, that they are impervious to international pressure, in fact there is a history up to the present of the Chinese government responding to international pressure," he said.

Roth said that despite potential threats by Beijing to shut off dialogue or curb business ties, Merkel should "call their bluff".

"She was quite up front (that) there are only so many things you can say publicly, that the German business community feels it has the most to lose even though Germany is one of the few nations with the clout to be able to say something," Roth said.

He also said Merkel had an obligation to back the 400 million Chinese people now using social media to make their voices heard.

"If you really want to change things in China, you've got to empower the engine that is most likely to produce change and that's the Chinese people," he said.

Merkel's office declined to comment on the talks with Roth and Shetty as they were not open to the media.

But a source close to her said they had covered "global human rights policy and hot spots covered by the organisations' work."