Angela Merkel, the German chancellor, declined on Wednesday to endorse David Cameron’s call for a major revision of the EU’s governing treaties to provide a legally watertight basis for British-led reforms before an in-out referendum in 2017.

A day of wooing by the prime minister, in which he made some of his most pro-European comments in over two years and signalled a retreat from plans to water down the fundamental principles of the EU’s freedom of movement, appeared to fall largely on deaf ears.

Speaking at a Downing Street press conference, after the prime minister had accompanied Merkel to the British Museum exhibition on objects covering 600 years of German history, the chancellor indicated there was little appetite in Berlin for treaty change to underpin changes in welfare and benefit rules.

She said there was a need for legislation but suggested that this would mainly be at the national level as member states consider aligning their welfare systems to avoid the abuse of freedom of movement.

Asked whether she would support treaty change, Merkel said: “As regards freedom of movement, as David quite rightly said, we have no doubt about the principle of freedom of movement being in any way questioned. But we also have to look at abuse of [those] principles. We are looking at legislation here. We want to see how this plays out at local level.

“We want to also say to our local authorities that abuse needs to be fought against so that freedom of movement can prevail and one has to take a very close look at the social security systems of individual member states – that are after all not part of communal law – to [see] to what extent they have to be adjusted to this situation. That is something we need to address together.”

The remarks by Merkel came after the Guardian reported that eyebrows were raised in Berlin at the prime minister’s call over the weekend for “full-on” treaty change to underpin his plans to curb in-work and out of work benefits for EU migrants. German officials have said Britain should bear in mind that Berlin’s failure so far to win support for treaty change for new eurozone governance suggest Britain will find it all but impossible to win support for treaty change.

Merkel sought common ground with Cameron as she voiced strong support for continued British membership of the EU and said she had worked closely with the prime minister on cutting the EU budget. She also repeated her suggestion, made during her last visit to London, that on EU reform “where there is a will there is a way”.

The chancellor’s highly cautious remarks came after the prime minister went out of his way to reach out to Merkel. He insisted that his plans to cut EU migration, outlined in his speech at the end of November, were designed to tackle the abuse of free movement and would not challenge the fundamental principles of free movement established in the EU’s founding treaty of Rome in 1957. He also made his pro-European comments since the summer of 2012 when some markedly upbeat remarks about the EU at a Brussels summit triggered a backbench backlash which led eventually to his referendum commitment.

Cameron said: “I support freedom of movement. But what I don’t support is the abuse of freedom of movement. That, as I set out in that very comprehensive speech, is what we need to change.”

In his pro-EU remarks, the prime minister said: “I don’t think the right answer is for Britain to leave the EU. The right answer is for EU reform and then a referendum. I have set out very clearly the changes in terms of immigration and welfare that need to take place. And they don’t break the principle that there should be free movement because many British people benefit from moving inside the EU to live and work in other countries.”

Nigel Farage, the Ukip leader, tweeted: “Mr Cameron made big overtures last month. But 48 hours with Mrs Merkel and he’s already repeatedly committing to open door immigration again.”

• The standfirst on this article was amended on 8 January 2015 to better reflect the story. It was further amended on 9 January 2015 because the earlier version said “failure to far” where “failure so far” was meant.