David Cameron claimed a proposed "emergency brake" to ease pressure from migrants on public services shows that Europe is "taking on board" his concerns.
The Prime Minister insisted his own plan for an outright four-year ban on migrants claiming in-work benefits remained on the table unless something "equally potent" was proposed.
European Commission president Jean-Claude Juncker is expected to give details of the "emergency brake" offer w hen the two men hold talks on the membership renegotiation in Brussels on Friday.
Reports have suggested the plan would see EU migrants barred from claiming benefits for four years when public services are deemed to be under strain.
Speaking on a visit to Aberdeen, Mr Cameron said: "I'm glad that others in Europe are now taking on board this issue and looking at strong alternatives to the proposal I put forward.
"The problem is clear, people coming to the UK getting instant access to our welfare system, that's the problem I put on the table and I've said my proposal remains on the table until I see something equally potent being brought forward.
"But what's good is that others in Europe are bringing forward ideas to address this problem so we have better control of movement of people into our country.
"I'm pleased that people are bringing forward ideas. It's a complex negotiation this, there's a lot of work to be done not just on migration but on the other things I've spoken about. Getting Britain out of ever closer union, maintaining our borders, making the single market work for us, making sure you can do well in Europe outside the euro.
"All these issues need to be sorted out, we've got some time now before the February European Council and I'm working as hard as I can to get the best deal for Britain."
It is not clear whether EU officials would need to give permission for the emergency brake mechanism to be used.
The idea, which the Prime Minister is also thought to have discussed with his Czech counterpart in Prague last week, has apparently gained traction as Mr Cameron struggles to finalise a deal in time for a key summit next month.
Mr Cameron cancelled a visit to Copenhagen on Friday in order to meet Mr Juncker and European Parliament president Martin Schulz in Brussels, and is due to have a working dinner with European Council president Donald Tusk in Downing Street over the weekend.
The Prime Minister will then fly to Hamburg on February 12, where he will have the opportunity to discuss his plans with Chancellor Angela Merkel as he delivers a speech on EU reform to the annual St Matthew's Day banquet.
Mr Tusk is due to publish "concrete proposals" for dealing with the UK's demands within the next couple of weeks, ahead of a crunch summit on February 18-19 at which Mr Cameron hopes to secure agreement with the 27 other EU leaders on a package of reforms.
Downing Street denied that the flurry of meetings were an indication of concern within Number 10 that the PM's timetable for an in/out referendum may be slipping.
Foreign Secretary Philip Hammond has admitted that a referendum this summer will be difficult if no deal is struck at the February summit, and "impossible" if it is not agreed at the following meeting in March.
Arron Banks, co-founder of the Leave.EU campaign, said: "People watching the slow-motion disaster overtaking Europe don't want an emergency brake on immigration, they want control of the steering wheel so we can avoid the car crash up ahead.
"We know the Prime Minister understands how inadequate this new proposal is himself because he dismissed it as 'some arcane mechanism which would probably be triggered by the European Commission and not by us' two years ago."