A dual US and German citizen was arrested on Sunday for allegedly attempting to burn down the US embassy in Tel Aviv, Israel, according to the justice department.

Officials said they arrested Joseph Neumayer, 28, at John F Kennedy Airport in New York. He was deported by Israeli authorities after he was found with explosive devices in a backpack near the embassy.

Mr Neumeyer appeared in court on Sunday and is being held in jail, the justice department said.

"This defendant is charged with planning a devastating attack targeting our embassy in Israel, threatening death to Americans, and President Trump's life," said Attorney General Pamela Bondi.

The arrest comes just days after a gunman killed two Israeli embassy staff members outside a Jewish museum in Washington DC.

Federal officials say Mr Neumayer arrived in Israel in April and on 19 May headed to the US Embassy in Tel Aviv with a dark-colored backpack.

The 28-year-old spat on an embassy guard as he walked by, the justice department said. When the guard tried to detain him, Mr Neumayer allegedly ran away, leaving behind a backpack with three Molotov cocktails, small bombs made with flammable liquids that are meant to start fires once they are lit and thrown.

Police later found Mr Neumeyer at his hotel where he was arrested, the justice department said.

Officials say he had posted on his social media account pledging to "burn down the embassy in Tel Aviv" and had called for "death to America, death to Americans".

Officials say Mr Neumeyer also threatened to assassinate Trump in social media posts on another account believed to be connected to him.

Mr Neumeyer was sent back on Sunday to the US, where he was arrested. He faces a maximum of 20 years in prison if convicted.

Last Wednesday, a young couple, Yaron Lischinsky and Sarah Lynn Milgrim, were shot dead outside an event at the Capital Jewish Museum in Washington DC.

Police identified the suspect as 30-year-old Elias Rodriguez from Chicago, who they say shouted "free Palestine" after he shot the couple.

Homeland Security Secretary Kristi Noem is expected to attend a memorial in Israel for the victims on Monday. (BBC)

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