Mr Morales has given foreign energy companies 180 days to agree to new contracts with Bolivia's state oil firm YPFB, which will then become the majority shareholder in energy companies operating there.
Along with Hugo Chavez of Venezuela and Chilean President Michelle Bachelet, he is at the vanguard of a leftist turn in Latin America which has Western oil companies and their political backers on edge.
"The Europeans must understand that we want to rebuild Bolivia and we're counting on democratic and peaceful structural changes, that is to say, without falling into armed conflict as in Colombia or Peru," Mr Morales said in an interview with news agency AFP.
"To that end, one of the changes is the nationalisation of natural resources. We have started to nationalise hydrocarbons and we will continue this process with other natural resources."
After Venezuela, Bolivia has the second largest reserves of gas in Latin America.
Mr Morales was speaking in Paris fresh from attending a three-day summit of EU and Latin American leaders in Vienna, where his May 1 decision to nationalise his country's energy sector stole much of the limelight.
In one pointed attack on Bolivia's new strategy, Austrian Minister of Finance Martin Bartenstein said last week: "If you want to harm your industry, you nationalise it. It's a step backwards, it's not encouraging investors".
British Prime Minister Tony Blair used a meeting with Brazilian President Luiz Inacio Lula da Silva to call on Mr Morales and Mr Chavez to use their energy resources "responsibly" and "in their own economic interest."
President Morales announced during the Vienna talks that no compensation would be paid to foreign companies affected by nationalisation but promised "genuine, long-lasting legal security" to foreign companies operating in Bolivia.
Elected leader of South America's poorest nation last December, Mr Morales said that "every investor has a right to recuperate his investment, but not to be master (of natural resources) and to draw exaggerated profits as is the case today".
"We want partners and not masters of resources," he said.
He said nationalisation would lift Bolivia out of its economic decline and provide work to thousands of underprivileged Bolivians.
"We do not want to recover the natural resources as such but to help create an additional labour force and make sure that less people find themselves obliged to come almost begging in Europe, from where they are expelled," he said.
Mr Morales said he was "very grateful" to French President Jacques Chirac whose "support has comforted me a lot". He also said Spanish Prime Minister Jose Luis Rodriguez Zapatero "perfectly understood" what he was trying to do for Bolivia.
After nationalisation, Bolivia's YPFB will oversee 56 gas fields, including those owned by foreign firms such as France's Total, the United States' Exxon-Mobil, Brazil's Petrobras and British Gas.