A Palestinian court on Monday sentenced a Palestinian man from east Jerusalem to life in prison with hard labor for trying to sell property in the Old City to an Israeli group.

The court said Monday that Issam Akel was convicted of "attempting to cut off Palestinian land and sell it to a foreign county."

The ruling underscored an increasingly visible battle in the city's eastern sector that has emerged following President Donald Trump's recognition of Jerusalem as Israel's capital a year ago. Since then, Israel has been taking steps to cement its control over the contested area while the Palestinians have attempted to push back to maintain their limited foothold.

One of those steps has been trying to prevent Palestinians in east Jerusalem from selling their properties to Jews — a major taboo that the Palestinian Authority is largely powerless to prevent.

The Palestinian Authority, which is barred by Israel from conducting political activity in Jerusalem, arrested Akel in Ramallah in October. Officials say he confessed to attempting to sell property in the Old City of Jerusalem to a Jewish settler group.

Living in east Jerusalem, Akel has Israeli residency rights and is permitted under Israeli law to sell his property to whomever he wants. Akel also is a U.S. citizen.

But the Palestinian Authority, which claims east Jerusalem as its capital, considers land sales to Israeli Jews to be treason and even punishable by death.

Palestinian President Mahmoud Abbas has never approved an execution, but he has punished Palestinians for selling land to Israeli settlers in the West Bank. He has never before attempted to apply the law in east Jerusalem, which Israel has annexed and considers an inseparable part of its capital.

Israel's Foreign Ministry declined comment. But in the past, Israel has called for Akel's release and arrested Palestinian officials in retaliation.

A U.S. official, meanwhile, said the U.S. was aware of the case. "When a U.S. citizen is incarcerated abroad, the U.S. government works to provide all appropriate consulate assistance," said the official, speaking on condition of anonymity under diplomatic protocol.

The conflicting claims to east Jerusalem lie at the heart of the Israeli-Palestinian conflict. Israel captured the area, home to the city's most sensitive religious sites, in the 1967 Middle East war and annexed it, claiming the entire city as its capital. But the annexation is not internationally recognized, and the Palestinians seek east Jerusalem as the capital of a future state.

Trump last year recognized Jerusalem as Israel's capital. Although he said the declaration was not meant to determine the city's final borders, the move was interpreted by both sides as siding with Israel. The Palestinians severed ties with the White House in response.

Marking the anniversary of his Fatah Party, Abbas on Monday said he would pre-emptively reject a peace plan the U.S. says it is preparing.

"Jerusalem is not for sale. We will never accept that," he said.