David Cameron will tell European leaders he is "determined to deliver" his reform agenda as he meets them for the first time since setting out his demands.
The Prime Minister acknowledged his proposals were "difficult" but insisted they were "do-able" and could benefit the European Union (EU) as a whole.
Mr Cameron, who was in Malta for an international summit bringing together European and African countries to discuss the migrant crisis, said he had worked "assiduously" to persuade his EU counterparts of the need for change.
Speaking during a visit to HMS Bulwark in Valletta harbour, he said: "I think people can see that Britain is absolutely determined to get these changes for the good of Britain but also for the good of Europe.
"My message will be 'yes, this is challenging, yes this is difficult, but it is do-able and if we do it we will actually have a better and stronger organisation that Britain can then vote to be part of'."
Asked how he thought his letter setting out his demands would be received by fellow leaders, he said: "I'm going to be looking forward to seeing my colleagues today.
"I have worked with them very assiduously, going round seeing every prime minister, every president, talking to them about why change is needed, why it would be good for Britain, good for Europe.
"It's challenging but it's do-able and I'm determined to deliver."
The Prime Minister set out his four key demands in a letter to European Council president Donald Tusk.
He called for "legally-binding principles" to protect the interests of non-eurozone countries like the UK, measures to improve competitiveness by cutting red tape, an end to "ever-closer union" and measures to curb immigration - including proposals for a four-year time limit before EU migrants can receive in-work benefits or social housing.
Lithuanian president Dalia Grybauskaite said some elements of the reforms proposed by the Prime Minister would be "acceptable", such as the drive to improve competitiveness in Europe - but warned other parts of the package would be "very difficult" and require full-scale treaty change.
As she arrived at the Malta summit, she said: "Some elements of course will be negotiable because it is for change of treaties and it is very difficult in Europe to do."