Funding, arming, and training neo-Nazi militias
As of March 2018, the United States is no longer funding the Azov Battalion, which is a neo-Nazi militia in Ukraine. An amendment to the annual omnibus spending bill prevented future funds from being routed to the group.
At least one American analyst has suggested that the Azov batallion is not a neo-Nazi group and that this is all propaganda created by Putin, but according to an article in The Hill, there is massive evidence that they are neo-Nazis. For example,
The U.N. and Human Rights Watch have accused Azov, as well as other Kiev battalions, of a litany of human rights abuses. In 2016, the Simon Wiesenthal Center caught Azov trying to recruit neo-Nazis in France; Brazilian authorities have uncovered similar attempts in Brazil. Azov’s official page on VK, a social media site used in Ukraine and Russia, features images of a white power tattoo and the Totenkopf symbol used by SS concentration camp guards and neo-Nazis today.
Lev Golinkin, "The reality of neo-Nazis in Ukraine is far from Kremlin propaganda." 11 September 2017
Azov’s neo-Nazi contingent has been confirmed by The New York Times, the Daily Beast, USA Today, Foreign Policy, The Guardian, the BBC, Reuters and the Simon Wiesenthal Center. [Links available in original article]
Lev Golinkin, "When we can’t agree to fight against neo-Nazis, we’ve reached a new low". 5 April 2018
It is unclear how much US funding went to the Azov Battalion before this, but they were a beneficiary. Azov was among the groups officially trained by the US and NATO in 2015.
The spokesman, Andrey Dyachenko, adds that “Only 10 percent to 20 percent of the group’s members are Nazis,” meaning that at least 100 to 200 Nazis may be about to receive intensive military training from US commandos.
The general situation in Ukraine
In 2012, the European Union warned Ukraine against associating with the Svoboda party, accusing it of “racist, anti-Semitic and xenophobic views.” In 2013, just prior to the revolution, John McCain was photographed at the Ukraine Maidan standing next to a member of Svoboda who had called for a fight against the "Muscovite-Jewish mafia".
In post-2014 Ukraine, Neo-Nazism is common both at the municipal level and at the state level. This is actively supported both by United States politicians and at the highest levels of the State Department:
In 2017, the New York Times printed the following editorial from Eduard Dolinsky, former executive director of the United Jewish Community of Ukraine:
Jewish cemeteries and synagogues have been vandalized. Nadia
Savchenko, a member of Parliament who became a national hero when she
was a pilot captured by Russia, recently appeared on television and
delivered an anti-Semitic screed. “I have nothing against Jews,” she
said. “I do not like ‘kikes.’ ” She added: “Jews possess 80 percent of
the power when they only account for 2 percent of the population.”
The majority of Ukrainian Jews share the desire to build a modern, democratic state, free from the endemic corruption we have lived with for the past 25 years. We support Ukraine’s choice to integrate with the West — which is why the Kremlin’s attempt to turn Ukraine’s Jews against Kiev during Moscow’s takeover of Crimea failed — and we have no more desire to live under Russian domination than other citizens.
[...] Western leaders must also stress that the glorification of organizations like O.U.N.-U.P.A. [the group behind the "Slava Ukraini" slogan] remains incompatible with Western values. We need the United States and the world’s help — for the memory of the slaughtered Jews and for Ukraine’s future.
Eduard Dolinsky, "What Ukraine’s Jews Fear" 11 April 2017
The BBC, for their part, claims that antisemitism has not increased, and that this is a fabrication by Putin. Their main source for this is an oligarch who seized control of the Ukrainian Jewish community in 2010.