The foundations, which promote democracy, free expression and civil rights, have come under growing political and legal pressure from Prime Minister Viktor Orban, who has stifled dissent and declared last week that "the era of liberal democracy is over". Orban, an avowed nationalist and critic of Western Europe's embrace of refugees, blamed Soros for much of the country's economic woes ahead of his recent reelection.
The Hungarian government could not be reached for comment.
It added, however, that it would "pursue all available legal avenues to defend the fundamental rights that are threatened by the legislation".
The law was one of a slew passed during Orban's past eight years in power that tightened regulations on the media, central bank, constitutional court and NGOs.
U.S. diplomat involved in accident allowed to leave Pakistan
Hall had killed a 22-year-old motorcyclist and injured another on April 7 in Islamabad after jumping a red signal. Hall is a certified envoy who enjoys himself diplomatic immunity, the sources added.
Addressing the "Stop Soros" legislation, the OSF's Gaspard said that it had "become impossible to protect the security of our operations and our staff in Hungary from arbitrary government interference".
Earlier this year, citing national security concerns, his government announced a so-called "Stop Soros" package of laws aimed at tightening rules for NGOs receiving funding from overseas. It would also impose a 25 percent tax on foreign donations to NGOs that back migration. Soros supporters argued the campaign also had anti-Semitic overtones, a claim the government rejected.
According to reports, George Soros' Open Society Foundations will close their office in the Hungarian capital and move to Berlin. The Foundations are taking appropriate steps regarding the safety and well-being of those affected by the office relocation.
Government pressure shows no sign of easing, however: Mr Orban said recently that he would not "shed crocodile tears" over the OSF, and he backed a pro-government magazine's publication of a list of more than 200 Hungarian NGO staff, academics and journalists whom it called "Soros mercenaries".