washington president donald trump expect announce soon decertify landmark international deal curb iran nuclear program senior administration official say thursday step potentially could cause 2015 accord unravel official speak condition anonymity say trump also expect roll broad u.s. strategy iran would confrontational trump administration frequently criticize iran conduct middle east trump call pact embarrassment bad deal ever negotiate weigh whether serve u.s. security interest face oct. 15 deadline certify iran comply term must allow iran ... obtain nuclear weapons trump say meet military leaders white house thursday add iranian regime support terrorism export violence bloodshed chaos across middle east must put end iran continue aggression nuclear ambition live spirit agreement ask decision whether certify landmark deal trump say hear iran shortly supporters say collapse could trigger regional arm race worsen middle east tensions opponents say go far ease sanction without require iran end nuclear program permanently iranian authorities repeatedly say tehran would first violate accord iran agree restrict nuclear program return lift international sanction cripple economy trump decline certify iran compliance u.s. congressional leaders would 60 days decide whether reimpose sanction tehran suspend agreement whether congress would will reimpose sanction far clear republicans democrats oppose deal approve 2015 little obvious appetite congress deal iran issue prospect washington could renege pact sign unite state britain france germany russia china european union iran worry u.s. ally help negotiate europeans hammer agreement work say european diplomat ask remain anonymous europeans repeat ... impossible reopen agreement period impossible french president emmanuel macron say last month alternative nuclear accord formally know joint comprehensive plan action jcpoa senior iranian diplomat tell reuters thursday end result trump expect move would isolate unite state since europeans would continue support many foreign investors tell us scar away iran market trump de-certifies deal diplomat say trump long criticize pact signature foreign policy achievement democratic predecessor barack obama administration consider oct. 12 trump give speech iran final decision make official say previously israeli prime minister benjamin netanyahu close ally trump last month say unless provision accord remove restrictions iran nuclear program time eliminate cancel fix nix netanyahu say speech u.n. general assembly annual gather world leaders sept. 19. many trump fellow republicans control congress also critical deal trump blast deal speech u.n. general assembly also sept. 19. abide agreement provide cover eventual construction nuclear program trump say add iran government mask corrupt dictatorship behind false guise democracy trump weigh strategy could allow aggressive u.s. responses iran force shi ite muslim proxies iraq syria support militant group trump defense secretary jim mattis tell congressional hear tuesday iran fundamentally compliance agreement also say unite state consider stay deal unless prove tehran abide u.s. national interest mattis ask senator whether think stay deal u.s. national security interest reply yes senator last week iran foreign minister say tehran may abandon deal washington decide withdraw state department official say trump administration fully commit address totality iranian threats malign activities seek bring change iranian regime behavior official say behavior include ballistic missiles proliferation support terrorism support syrian president bashar al-assad unrelenting hostility israel consistently threaten freedom navigation persian gulf cyber attack unite state ally human right abuse arbitrary detentions u.s. citizens jcpoa expect contribute regional international peace security iran regime everything power undermine peace security state department official add move also would represent another step trump would undo key part obama legacy trump move decertify accord would mark another example walk away international commitments pursue nationalist america first agenda previously announce plan abandon paris climate accord ambitious 12-nation trans-pacific partnership tpp trade deal two key obama achievements trump expect decertify iran nuclear deal official say