Updated

An American who left the United States to join an Al Qaeda-linked group in Somalia is strongly condemning President Obama’s efforts to seek “a new beginning” with the Muslim world, mocking Obama's “magic of charisma” and warning of more attacks against U.S. interests.

“Despite the fact that you have been ... forced [by Muslim fighters] to at least pretend to extend your hand in peace to the Muslims, we cannot and shall not extend our hands,” said the man in the audiotape, identified by the Washington-based Middle East Media Research Institute (MEMRI) as Abu Mansour al-Amriki. “Rather, we shall extend to you our swords, until you leave our lands.”

The 20-minute audiotape, called "The Beginning of the End," was posted Thursday on several jihadist web sites as a direct response to Obama’s much-publicized speech in Cairo on June 4, when he promised “a new beginning between the United States and Muslims around the world.”

“Let this not come as a surprise to those who are mesmerized by Obama’s speech in Cairo, our positions ... have not changed in the least,” al-Amriki said, in the transcription provided by MEMRI. “If we study his words carefully, we can note very clearly that this new beginning is still heavily based upon American interests … [Obama spoke] not because he loves the Muslims he lived with in Indonesia, as a boy, but rather, it is because the only way to defeat the Muslims is by distracting them with this temporary life.”

Al-Amriki, speaking in English throughout the audio tape, also said Obama’s speechwriters made “one major miscalculation.”

“A Muslim doesn’t look to peace, security, education, work, or the love of any other number of things as his ultimate goals,” al-Amriki said. “Instead, a Muslim is always working and striving to please the one true Creator."

Click here to listen to the tape.

In his speech in June, Obama said he was seeking a relationship with the Muslim world “based on mutual interest and mutual respect.”

“I consider it part of my responsibility as president of the United States to fight against negative stereotypes of Islam wherever they appear,” he said at Cairo University. “But that same principle must apply to Muslim perceptions of America. Just as Muslims do not fit a crude stereotype, America is not the crude stereotype of a self-interested empire.”

But Obama also warned that Al Qaeda has “affiliates in many countries and are trying to expand their reach.”

Somalia is one of those countries. An Al Qaeda-linked group known as al-Shabaab has been warring with the moderate Somali government since 2006, and the fighting has turned Somalia into a state of anarchy. U.S. officials say that if al-Shabaab prevails, Somalia could turn into a haven for Al Qaeda and other terrorist groups.

In the past year, scores — if not hundreds — of Muslims from several Western countries have left their homes to train and fight with al-Shabaab in Somalia. In fact, the FBI has been looking into how dozens of Somali-American men from the Minneapolis area were recruited to join al-Shabaab late last year. A grand jury in Minneapolis has been investigating the case for several months, and a series of indictments is expected to be announced soon.

Al-Amriki joined al-Shabaab before the new wave of recruits from Minneapolis. A law enforcement official told FOX News earlier this year that al-Amriki, described as in his late 20s or early 30s, is originally from the United States but has been in Somalia "for some time." It’s unclear what al-Amriki’s given name is.

His new audiotape is an attempt to recruit even more foreign fighters.

“As you have presented to us a new beginning, we reply by saying that by the permission of Allah, this beginning is ... the beginning of the end — the end of the tyranny and oppression so common to America,” al-Amriki said. “This is the cause of the entire Muslim [world], and it is being carried even by those who are considered legal citizens of your own country, according to your own laws.”

Al-Amriki also rejected Obama’s promise of a “change” from the previous administration.

“As far as your claims with regard to improving some of the policies of Bush,” al-Amriki said, “you are claiming that Guantanamo Bay will be closed down early next year. We won’t be satisfied until all the Guantanamos ... around the world have been closed, and all of the Muslim prisoners — male and female — have been released. You claim that you will fully pull out all of your troops from Iraq by 2012. We won’t be satisfied until you pull out all of your troops from all of the Muslim lands.”

In the audiotape, al-Amriki made no mention of recent U.S. assistance to the Somali government, perhaps helping U.S. authorities determine when the audiotape was made.

The U.S. government announced in late June that, for the past several weeks, it had been supplying the Somali government with weapons, military training and humanitarian aid.

"We are concerned [about Somalia]," State Department spokesman Ian Kelly said at the time. He said the U.S. government hopes to help "repel the onslaught of extremist forces which are intent on ... spoiling efforts to bring peace and stability to Somalia.”

The new audiotape is al-Amriki's second high-profile message. In April, he showed his face for the first time in a 30-minute recruitment video posted online. The video was a highly polished production, featuring anti-American hip-hop and sporadic images of Usama bin Laden.

In the video, al-Amriki purportedly leads a group of al-Shabaab militants in an ambush of pro-government forces in Somalia.

Speaking about one man killed in the fight, al-Amriki said in the video, “We want to inform his family that he was one of the best brothers here. ... We need more like him, so if you can encourage more of your children and more of your neighbors, anyone around, to send people like him to this jihad it would be a great asset for us."