Another 66 percent of immigrants come to the country with ties to family members, and 22 percent come because of humanitarian needs or through seeking asylum.
Watch his remarks from the White House Rose Garden live.
Under the proposals, the United States would welcome better educated people and those with job offers, while pushing back the large-scale influx of poor immigrants and asylum seekers overwhelming immigration facilities on the US-Mexican border.
Mr Trump's new plan has been months in the making, a project of his son-in-law, Jared Kushner, who has been meeting privately with business groups, religious leaders and conservatives to find common ground among Republicans on an issue that divides the party. Even within the White House, there are divisions over how to approach immigration policy, though one administration official disputed that.
Republican Senator Lindsey Graham, a key ally of Trump in Congress, signalled his lack of enthusiasm by releasing his own proposal yesterday and commenting: "The White House's plan is not created to become law, (while) this is created to become law".
The plan does not address what to do about the millions of immigrants already living in the country illegally, including hundreds of thousands of so-called Dreamers - children of undocumented migrants who came to the US illegally but are protected from deportation by the Deferred Action for Childhood Arrivals (DACA), a policy Trump has tried to end.
What Trump's plan doesn't include is any mention of the Deferred Action for Childhood Arrivals program. Mr Trump also wants to create a self-sustaining fund, paid for with increased fees, to modernise ports of entry. And he again proclaimed that work on his long-touted wall was underway.
"That is a wall that is desperately needed", he said. "As we close the gaps in our physical framework, we must also close the gaps in our legal framework".
Naturally there was a great deal of skepticism from Democrats even before Trump announced his proposals; they're particularly concerned about "merit" as opposed to full acceptance of any family wanting to come to this country for any reason.
On Wednesday, Republican Sen.
Trump is scheduled to roll out the plan Thursday afternoon at the White House. Under Trump's proposal, the White House says almost 60% would enter due to employment and skill. Prior to Trump's speech, Press Secretary Sarah Sanders said plans for DACA were "left out on objective".
In another tweet, he said "I will continue working w/ the Trump Administration & my Senate colleagues to move toward a merit-based immigration system that is focused on bringing in the best & brightest from around the world who wish to come to the USA legally to work & make a better life for themselves".
Visa applicants would receive points for age, English proficiency and offers of employment at a certain wage threshold; to protect low-wage American workers.
Under the new plan, the USA would award the same number of green cards as it now does.
Just before the White House unveiled its immigration proposal, the mood on Capitol Hill was largely one of shrugs. Opponents on the left-who were never going to support a Trump plan, regardless of its merits-say it's a non-starter because it doesn't include a path to citizenship for those who illegally crossed the border as minors.
"I don't see that the will is there to do it".
"I don't see that the will is there to do it", West Virginia Senator Shelley Moore-Capito, a Republican, told CNN. Susan Collins of ME, objected to its failure to account for the young Dreamers. Kushner presented the plan to Senate Republicans Tuesday, Fox News reports, to positive if uncertain response.