Secretary of State Mike Pompeo has toured a Jewish settlement in the Israeli-occupied West Bank - the first such visit by a top US official.
The trip to Psagot came a year after Mr Pompeo said the settlements did not contradict international law, reversing a long-held US position.
The declaration outraged Palestinians, who oppose settlements on land they claim for a future independent state.
Mr Pompeo later paid a similar visit to the occupied Golan Heights.
President Donald Trump last year officially recognised Israeli sovereignty over the strategic plateau, which Israel seized from Syria in the 1967 Middle East war and annexed in 1981.
Mr Trump is a close ally of Israeli Prime Minister Benjamin Netanyahu, and analysts say Mr Pompeo's actions could be seen as a valedictory gesture before he and the president leave the world stage.
Mr Pompeo arrived in Israel on Wednesday for what is likely to be his last trip to Israel before leaving office in January.
After meeting Mr Netanyahu in Jerusalem on Thursday morning, he announced that the state department would declare as anti-Semitic the global Boycott, Divestment and Sanctions (BDS) movement, which campaigns for a complete boycott of Israel over its policies towards the Palestinians.
Israel says that BDS opposes the country's very existence and is motivated by anti-Semitism. BDS rejects the charge, saying Israel is using it as a cover for its actions.
Mr Pompeo also told reporters that "for a long time the state department took the wrong view of settlements" in the West Bank.
"It took a view that didn't recognise the history of this special place and instead now today the United States department of state stands strongly to the recognition that settlements can be done in a way that's lawful and appropriate and proper," he added.
He then travelled by helicopter to the Psagot winery, in a Jewish settlement close to Ramallah.
More than 600,000 Jews live in about 140 settlements built since Israel's occupation of the West Bank and East Jerusalem in the 1967 Middle East war. Most of the international community considers the settlements illegal under international law, though Israel disputes this.
While Psagot winery staff would not comment officially on this visit in advance, the BBC was shown one of the last bottles of "Pompeo" red - a blend of shiraz, cabernet sauvignon and merlot, described on the label as "refreshing, fruity and beautifully balanced".
It was named after the US secretary of state declared last year that settlements were "not, per se, inconsistent with international law". Most countries still believe that they are.
The Psagot winery has a vineyard on privately-owned Palestinian land and is owned by US donors to the Trump administration.
It is well-known for its international efforts to have its wines labelled as coming from Israel. However, European courts have rejected its attempts to mark bottles in this way, saying that products manufactured in West Bank settlements need to be labelled as such.
Following his visit to Psagot, Mr Pompeo issued a statement saying the US would require goods imported from areas "where Israel exercises the relevant authorities" to be marked as "Israel", "Made in Israel", or "Product of Israel".
The guidelines, he said, applied "most notably" to the 60% of the West Bank, classified as "Area C" under the Oslo Accords, that is under full Israeli military and civilian control and where much of the settler population lives. It includes the Jordan Valley and many Palestinian communities.
Exports from West Bank areas controlled by the Palestinian Authority had to be labelled "West Bank", and those from Hamas-controlled Gaza marked as "Gaza", Mr Pompeo added, arguing that the territories were "politically and administratively separate and should be treated accordingly".
Palestinian leaders called Mr Pompeo's actions a provocation.
Nabil Abu Rudeineh, a spokesman for Palestinian Authority President Mahmoud Abbas, said: "Pompeo's visit to occupied land is an active participation in the occupation."
Syria has also appealed to the United Nations to condemn the "provocative" visit, calling it "a flagrant violation" of Syrian sovereignty, a government source told state media.
President-elect Joe Biden is expected to reverse Mr Pompeo's declaration on settlements, but he has said he will not undo Mr Trump's decision in 2017 to recognise of Jerusalem as Israel's capital.
Mr Pompeo later became the first US secretary of state to visit the Israeli-occupied Golan Heights, visiting a hilltop overlooking the Syrian-held part of the plateau with Israeli Foreign Minister Gabi Ashkenazi.
"You can't stand here and stare out at what's across the border and deny the central thing that President Trump recognised, that previous presidents had refused to do, that this is a part of Israel, and a central part of Israel," he said.
He also condemned what he described as calls "in the salons in Europe and in the elite institutions in America" for Israel to return the Golan to Syria.
"Imagine with [Syrian President Bashar] al-Assad in control of this place, the risk, the harm to the West and to Israel and to the people of Israel," he added.
Israel's annexation of the Golan has not been recognised by the rest of the international community, and Syria demands the return of the territory. It called Mr Trump's declaration "a blatant attack on its sovereignty".