The plan includes a call for quotas on the number of migrants each EU country would be required to take in, based on population size, gross domestic product and unemployment rate, as well as the number of past applications received.
The proposals will likely be controversial, with immigration a hot-button issue in many of the 28 EU member nations.
Germany backs the plans, for example, but the UK government strongly opposes them.
What's not in question, though, is that something must be done to curb the often deadly trafficking of migrants across the Mediterranean.
Presenting the new migration policy on Wednesday, EU foreign policy chief Federica Mogherini said: "With this bold agenda, the European Union has proven itself ready to address the plight of those escaping from wars, persecution and poverty.
"Migration is a shared responsibility of all member states and all member states are called now to contribute to tackling this historical challenge."
EU foreign and defense ministers are due to meet as soon as Monday to take some initial decisions on measures outlined in the proposals, she said.
Mogherini on Monday asked the United Nations to authorize military action to destroy boats
used illegally to smuggle people from Africa to Europe.
Many of the migrants are from sub-Saharan Africa and Syria, or are foreign workers who have lost their livelihoods. They know that people-traffickers can take them to Europe from Libyan shores, often arriving in Italy.
But many die at sea. More than 3,400 migrants died in 2014, according to estimates from the U.N refugee agency, many more than in the previous year.
Mogherini: 'Huge responsibility we all share'
In her Monday speech to the U.N. Security Council, Mogherini said 2015 looked likely to be worse yet. The U.N. refugee agency estimates that close to 2,000 have already died attempting the journey so far this year.
"Our first priority must be to save lives; to prevent the loss of lives at sea. We believe, in the European Union, that this is a huge responsibility we all share, not only as Europeans but also globally," Mogherini said.
She also assured those listening that "no refugees or migrants intercepted at sea will be sent back against their will" and that their rights under the Geneva Conventions would be respected.
Answering reporters' questions Wednesday, Mogherini restated the EU's commitment to those rights, but clarified that not every migrant rescued at sea would be allowed to stay in Europe. However, those individuals will not be returned to unsafe countries or sent back before their case is properly considered, she said.
European Commission Vice-President Frans Timmermans also made the point that the return of migrants whose asylum claim was not accepted was "a cornerstone of the plan."
Other proposed elements include:
• Additional funding for operations by Frontex, the EU's border agency, in the Mediterranean to help rescue migrants in trouble and deter people smugglers;
• An extra 50 million euros ($56 million) for an EU-wide resettlement scheme, to offer 20,000 places across member states to displaced people in clear need of international protection in Europe;
• A possible joint security operation in the Mediterranean to dismantle traffickers' networks by capturing and destroying their boats;
• Working with migrants' countries of origin and nations that are major transit points to try to stem the flow of migrants before they are put on boats, including by helping them to strengthen their borders;
• Working with the International Organization for Migration and U.N. refugee agency to set up a pilot center in Niger, a major transit route for migrants
, that would try to limit the number of people coming from West Africa;
• Introducing a new policy on legal migration to reduce the incentive for people to seek to enter illegally and making sure all EU states share a common policy on asylum process.
UK Home Secretary Theresa May argued in an opinion piece published Wednesday by The Times of London that the introduction of quotas for migrants would only encourage more people to make the hazardous journey.
Instead, May said, "The EU should work to establish safe landing sites in North Africa, underpinned by an active programme of returns."
She also rejected Mogherini's remarks on not sending migrants back to their countries of origin, saying, "Such an approach would only act as an increased pull factor across the Mediterranean and encourage more people to put their lives at risk."
And she called for differentiation in the way asylum seekers and economic migrants are treated.
"We must distinguish between those genuinely fleeing persecution and economic migrants crossing the Mediterranean in the hope of a better life," she wrote.
Under EU treaties, the United Kingdom, Ireland and Denmark have a special status allowing them to opt out of the proposed migration measures.
More than a third of asylum seekers from Syria
According to figures released by Eurostat
on Tuesday, 27 EU member states "granted protection status to 185,000 asylum seekers in 2014, up by almost 50% compared with 2013." No figures were available for Austria.
Of those asylum seekers whose claims were accepted, 37% -- or 68,400 people -- were from war-torn Syria. Germany and Sweden combined took in 60% of those asylum seekers.
Eritrea and Afghanistan were the next most common countries of origin, with their citizens each making up 8% of those granted protection. More than three-quarters of the Eritreans were taken in by three countries: Sweden, the Netherlands, and Britain. More than half the Afghans were taken in by Germany and Italy.
Others came from Iraq, Iran, Somalia, Pakistan, Russia and elsewhere.