WASHINGTON (Reuters) - House Speaker Paul Ryan said on Thursday that Republicans next year will unveil a plan to replace Obamacare in its entirety, as part of a "pro-growth" agenda that he believes should also include cutting welfare programs and taxes.

Ryan said even if President Barack Obama will not sign them into law in his last year in office, the Republican majority in Congress must produce proposals to demonstrate "what our ideal policy would be looking forward to 2017 and beyond."

"Put together a positive agenda and take it to the American people," he urged members of his party. The most urgently needed action, Ryan said, was to replace the Patient Protection and Affordable Care Act, as Obamacare is officially called.

"Next year, we are going to unveil a plan to replace every word of Obamacare," Ryan said in a speech at the Library of Congress, which his office billed as his first major address as speaker, a job he has held for a little over a month.

Republicans have been vowing for years to repeal and replace Obamacare, the president's signature healthcare initiative that Democrats passed in 2010 over united Republican opposition. Democrats say the act is insuring more Americans and helping to slow the growth in healthcare spending.

Republicans have never been able to agree on a replacement plan. Ryan said one idea was to offer an individual tax credit to help people pay for health insurance premiums.

Ryan, a 2012 vice presidential candidate, said Republicans had watched Obama transform the country "with great dismay."

But he said his party should focus on ideas in the 2016 election year instead of demonizing their opponents, a message that contrasted with the polarizing language of other Republicans, including some on the presidential campaign trail.

The speaker also said he favored simplifying the U.S. tax code by taking the seven income tax rates that exist now and collapsing them to two or three.

While saying Medicare and Social Security will be there "when you need them," Ryan also suggested a revamp of safety net programs. He said Medicaid, food stamps and housing assistance were trapping people in poverty.

"In 1996, we created a work requirement for welfare. But that was just one program. We have to fix all the others now. I'd combine a lot of them and send that money back to the states for better poverty-fighting solutions. Require everyone who can to work," Ryan said.

(Reporting by Susan Cornwell; editing by Bill Rigby and G Crosse)