The last known Nazi collaborator living in the United States -- a 95-year-old former camp guard who played an "indispensable role" in the murders of thousands of Jews -- was deported to Germany from his New York City home early Tuesday morning, completing what the U.S. ambassador to Germany called a "difficult task."

Richard Grenell, the U.S. ambassador who arrived in Germany earlier this year after political maneuvering by Democrats held up his nomination for months, told "FOX & friends" in an exclusive interview that President Trump — who is from New York — instructed him to make the removal of Jakiw Palij a priority. Grenell said the new German government, which took office in March, brought "new energy" to the matter.

"It's really a credit to President Trump, who was very clear about this case, made clear he wanted this individual out of the United States," Grenell said, later adding, "it's a great day for the United States to have this man out of our country."

Immigration and Customs Enforcement agents on Tuesday implemented a deportation order against Palij that dated to 2004. But kicking out Palij, who immigrated to the U.S. in 1949 and became a citizen in 1957 after concealing his Nazi background, was no easy task.

Grenell said the deportation came after months of diplomatic negotiations, and was "difficult" because Palij is not a German citizen and was stateless after losing his citizenship in the U.S.

"[Germany] had a moral obligation, not necessarily a legal one, because he worked in the name of the then-German government," he told "FOX & friends."

The ambassador praised Germany's new foreign and interior ministers who both "wanted to work with President Trump to make this happen." He also said that Secretary of State Mike Pompeo was "aggressive" about the case.

Palij admitted to Department of Justice officials in 2003 that he trained at a Nazi camp in German-occupied Poland. Court documents indicated that men who trained at the SS Training camp in Trawniki carried out the Nazi regime’s plan to murder Jews in Poland.

The 95-year-old also served as an armed guard at the adjacent Trawniki Labor Camp – where he played an “indispensable role” in the death of roughly 6,000 Jews who were killed in one of the single largest massacres of the Holocaust in 1943, according to the statement.

Palij, who claimed he was working on a farm and in a factory during World War II, had his U.S. citizenship revoked in 2003 by a federal judge, and ordered to be deported a year later. His appeal was denied in 2005.

After the war, Palij maintained friendships with other Nazi guards who the government says came to the U.S. under similar false pretenses. And in an interesting coincidence, Palij and his wife purchased their Queens home near LaGuardia Airport in 1966 from a Polish Jewish couple who had survived the Holocaust and were not aware of his past.

“Through extensive negotiations, President Trump and his team secured Palij’s deportation to Germany and advanced the United States’ collaborative efforts with a key European ally,” the statement read.

The State Department later issued a statement saying Germany has re-admitted Palij. As for what will happen to Palij in Germany, Grenell said "it's in the hands of the Germans" to figure out what to do with him next.

"The fact is we have a president who really wants to fight for the American people, make sure that the rule of law is followed," he told "FOX & friends."

In a special ceremony at the White House on Monday, Trump honored two agencies -- Immigration and Customs Enforcement and Customs and Border Protection -- however, as ABC News noted Palij was not mentioned.

The Associated Press contributed to this report.