WASHINGTON - Having returned from North Korea on Thursday, Secretary of State Mike Pompeo will embark on talks to persuade allies in Europe, the Middle East and Asia to press Iran to return to negotiations over its nuclear and missile programs, US officials said.The open question is whether the allies, and above all Iran, will agree to resume full-fledged talks, having just seen the United States withdraw from the 2015 Iran nuclear deal and renege on its promises under the landmark arms control accord.The US hope is that Iran will be dragged to the table by the resumption of US sanctions - and possibly the imposition of more - which would penalize European and other companies and likely cripple Iran's oil-driven economy.A senior State Department official said discussions with Britain, France and Germany, as well as Japan, Iraq and Israel on next steps had already taken place since US President Donald Trump on Tuesday pulled out of the nuclear pact."There will be an effort to go out globally and talk to our partners around the world who share our interests. That is the first stage," a senior State Department official said of plans for talks by Pompeo and his chief Iran negotiator, Brian Hook."The composition of what happens when we sit down with the Iranians is several stages out," the official said, adding that talks would focus on how to raise pressure on Iran "in a way that is constructive and conducive to bringing them to the negotiating table."Trump's decision opens the door to greater US confrontation with Tehran and strains relations with America's closest allies, current and former diplomats said.Washington has given grace periods of 90 days to six months for companies to wind down their trade with Iran. Some allies, like France, will push for exemptions from US sanctions to protect their companies.Even though companies can seek US Treasury licenses to continue operating in Iran beyond the deadlines, the threat of US sanctions will likely force them out, experts say.Pompeo returned to the United States overnight after meeting with North Korean leader Kim Jong Un and helping to return three Americans who had been detained there. The families of Americans jailed in Iran have also appealed to Pompeo to help secure their release.US Vice President Mike Pence, who greeted the Americans upon their arrival from North Korea, said although the Trump administration withdrew from the Iran pact, it is always interested in bringing Americans home."Now we're engaging on the possibility of a new deal which may create opportunities for... addressing issues of Americans that are detained in Iran but checking the extraordinary malign influence and support for terrorism that Iran continues to propagate across the region," Pence told CBS News in an interview that aired on Thursday.NEW DEAL?Companies will also have to assess whether they could face revived secondary sanctions, which would target sectors of the Iranian economy including energy, petrochemicals, shipping, financial and banking, experts say."The goal is ultimately to reach a point where we sit down with the Iranians and negotiate a new deal, but I don't think we're at that point today, or will be tomorrow," the State Department official said."The ultimate goal is to lay the groundwork for getting everyone back to the table and negotiating a new deal."Several US officials have acknowledged there is no "Plan B" if Washington cannot win the support of allies - and Iran - to negotiate a new, expanded agreement that would end Iran's nuclear program, restrain its ballistic missiles program, and curb its support for groups in Syria, Lebanon, Yemen and Iraq."The goal is to prevent Iran from ever developing or acquiring a nuclear weapon and the detail beyond that is something we are going to have to flesh out," the official added.Andrew Peek, deputy US assistant secretary for the bureau of Near Eastern Affairs at the State Department, denied the pressure campaign aimed to force regime change in Iran."No, we are trying to change the regime's behavior," he told reporters on a conference call, adding that Washington would use diplomacy to convince allies to follow the US sanctions lead.Peek acknowledged there are some "diplomatically tactical disagreements" with Europeans but said those differences could be overcome. "This is something where we cajole, we urge, we prod, which have proven effective," he added.While the parties were unable to agree on a supplemental pact to the 2015 nuclear deal, the senior official said a new round of talks would "pick up all of the work" done so far.