Palestinian President Mahmoud Abbas walks inside the hospital in Ramallah, in the occupied West Bank May 21, 2018. Palestinian President Office (PPO)/Handout via REUTERS

RAMALLAH, West Bank (Reuters) - Palestinian President Mahmoud Abbas, who has been hospitalized with a lung infection since the weekend, should be discharged by Friday, a doctor treating him said on Wednesday.

Abbas, 82, was admitted to hospital on Sunday in the West Bank city of Ramallah. Doctors initially said the veteran leader had gone in for medical tests after ear surgery five days earlier, but on Monday they said he had a lung infection.

A heavy smoker, Abbas was hospitalized in the United States for medical checks in February during a trip to address the U.N. Security Council.

“(Abbas) is recovering and the medical team has decided that once we are sure everything is in order, within two days, he can leave,” Yasser Abu Safiyeh, one of the doctors treating Abbas at Ramallah’s al-Itishari hospital told reporters.

Abbas was filmed on Tuesday walking in the hospital wearing a dressing gown. The official WAFA news agency said he had held phone conversations with a number of Arab leaders and had met Palestinian officials.

The Western-backed leader became president after the death in 2004 of his predecessor, Yasser Arafat. Abbas pursued U.S.-led peace talks with Israel but they broke down in 2014.

Abbas’s democratic mandate expired eight years ago - there has been no presidential election since 2005 and the term of office is only five years. His authority is essentially limited to the Israeli-occupied West Bank, with the Islamist group Hamas in control of the Gaza Strip.

Abbas has no formal deputy in the Palestinian Authority. In theory, the speaker of parliament would take over as president on an interim basis if the president were to die in office. But the speaker’s role is held by a Hamas representative, and Abbas’s Fatah faction would be likely to dispute the constitutional legitimacy of his taking over.

Taking on more vestiges of statehood, the Palestinians have joined United Nations Conference on Trade and Development, the United Nations Industrial Development Organization and the Convention on the Prohibition, Stockpiling and Use of Chemical Weapons, U.N. Middle East envoy Nickolay Mladenov told the Security Council on Wednesday.