Iranian foreign minister lashes out at Obama via Twitter The apparent efforts by Iran over the past few days to re-connect with the United States and other U.N. countries took an abrupt turn Monday when one of the country's top officials lashed out at President Obama. Foreign Minister Javad Zarif used Twitter to accuse Obama of imposing "illegal" sanctions on his country -- an argument he has repeatedly made -- and of doing a "flip flop." That was an apparent reference to the president meeting Monday with Israeli President Benjamin Netanyahu, Iran's neighbor and bitter enemy. Pres. Obama's presumption that Iran is negotiating because of his illegal threats and sanctions is disrespectful of a nation, macho and wrong," Zarif tweeted. President Obama needs consistency to promote mutual confidence. Flip flop destroys trust and undermines US credibility," he wrote in a second tweet. Zarif's remarks come one day after he said Iran is open to negotiating about its top-secret nuclear program, including possible inspections, but that the United States must "dismantle its illegal sanctions." His comments followed a 17-minute phone conversation Friday between Obama and Iranian President Hassan Rouhani, ending a three-decade freeze that began during Iran's 1979 revolution. "Iran is prepared to start negotiating," Zarif told ABC News on Sunday. Sanctions against Iran that started in 1979 were expanded by the U.S. several years ago. The U.N. Security Council imposed sanctions in 2006 after Iran refused to suspend its nuclear enrichment program. Obama said after Friday's call he thinks the two countries can reach a "comprehensive solution" on Iran's nuclear program, and that he and Rouhani had both directed their diplomats to pursue an agreement. During Netanyahu's face-to-face meeting Monday with Obama, he cautioned the U.S. not to let up on sanctions against Iran and called Rouhani's latest diplomatic push a "smiley campaign." Western officials saw Rouhani's remarks before the U.N. General Assembly last week as conciliatory in tone, and Secretary of State John Kerry has begun working with other diplomats to potentially re-launch talks over Iran's nuclear program. But, visiting the White House on Monday, Netanyahu said Iran's "conciliatory words" have not yet been met by "real action." Obama, sitting beside Netanyahu, agreed that "words are not sufficient" and Western leaders need to see "actions." Netanyahu, who contends Iran is using the gestures as a smoke screen to conceal an unabated march toward a nuclear bomb, said before boarding his flight to the U.S. that: "I will tell the truth in the face of the sweet talk and the onslaught of smiles." The Associated Press contributed to this report.