WASHINGTON >> House Speaker Paul Ryan is proposing to secure U.S. borders by overhauling the immigration system and installing robust defenses to keep out extremists, criminals and drug cartels.

The plan is part of a national security strategy the Wisconsin Republican will unveil on Thursday. It’s a key plank in a broader policy blueprint he is crafting that seeks to unite Republicans amid the frequent distractions triggered by Donald Trump’s unconventional presidential campaign.

The focus on immigration and border protection tracks with one of the cornerstones of Trump’s platform. Ryan calls for the use of “high fencing” along border areas, but steers clear of the billionaire candidate’s signature issue: building a wall to keep people from illegally entering the United States from Mexico.

Trump also has proposed banning all Muslims from entering the country, which Ryan has rejected.

“America must secure the border once and for all by accelerating the deployment of fencing, technology, air assets and personnel,” Ryan’s strategy reads. “We also must overhaul our immigration system for national security reasons.”

Ryan said the U.S. has repeatedly failed to eliminate serious vulnerabilities in the immigration system, citing the inability to verify comprehensively whether visitors to the U.S. actually leave when their visas expire.

The plan also hammers President Barack Obama for what Ryan and other Republicans have said is a failed foreign policy. He listed Obama’s refusal to enforce “its red line in Syria” and the international nuclear deal with Iran among the examples.

Ryan outlines in broad strokes a series of measures for defeating the Islamic State group and other extremists. He advocates relying on “local forces” in Iraq and Syria to defeat militants, but indicates Republicans must be prepared to deploy U.S. troops if necessary.

“We cannot take options off the table, because doing so telegraphs weakness to our enemies and emboldens them,” he said.

Ryan’s policy blueprint is aimed at defining what Republicans are for, not just what they are against.

In a video posted last week, he made an appeal to frustrated Republican voters who are supporting Trump, the party’s presumptive nominee.

“We can get angry and we can stay angry or we could channel that anger into action,” Ryan said in the video.

The few specifics Trump has offered on defense and foreign policy issues have rattled Republicans and unnerved U.S. allies. The billionaire candidate has pledged, if elected, to bring back the use of waterboarding — it causes the sensation of drowning — and worse against captured militants. Congress has outlawed waterboarding along with other so-called enhanced interrogation techniques.

Trump also said he would order the military to kill family members of extremists who threaten the U.S., a position he has since retreated from after being heavily criticized. And he’s questioned whether NATO and America’s other key alliances have become obsolete.