Israel's increased attacks and forcible transfers of Palestinians "raise concerns over ethnic cleansing" in the Gaza Strip and West Bank, the United Nations said Thursday.

The cumulative impact of Israel's military conduct during the war in Gaza and blockade of the territory, has inflicted living conditions "increasingly incompatible with Palestinians' continued existence as a group in Gaza", said the UN human rights office.

SYDNEY, Feb 19 (Reuters) - Australian police said on Thursday they had launched an investigation after a threatening letter was sent to the country’s largest mosque, the third such incident in the lead-up to the Muslim fasting month of Ramadan.

The letter sent to Lakemba Mosque in Sydney’s west on Wednesday contained a drawing of a pig and a threat to kill the "Muslim race", local media reported.

Police said they had taken the letter for forensic testing, and would continue to patrol religious sites including the mosque, as well as community events.

By Nidal al-Mughrabi and Maayan Lubell

CAIRO/JERUSALEM, Feb 19 (Reuters) - Hamas is cementing its hold over Gaza by placing loyalists in key government roles, collecting taxes and paying salaries, according to an Israeli military assessment seen by Reuters and sources in the Palestinian enclave.

Hamas’ continuing influence over key Gaza power structures has fuelled widespread scepticism about the prospects of U.S. President Donald Trump’s peace plan, which requires the militant group to give up its weapons in exchange for an Israeli military withdrawal from the territory.

By Steve Holland, Simon Lewis and Samia Nakhoul

WASHINGTON, Feb 19 (Reuters) - U.S. President Donald Trump will preside over the first meeting of his Board of Peace on Thursday with unresolved questions on the future of Gaza hanging over an event expected to include representatives from more than 45 nations.

The disarmament of Hamas militants, the size of the reconstruction fund and the flow of humanitarian aid to the war-battered populace of Gaza are among the major questions likely to test the effectiveness of the board in the weeks and months ahead.

Oil prices rose to multi-month highs while global stocks mostly retreated as markets weighed sharpening rhetoric from President Donald Trump on Iran suggesting a military strike was more likely.

Brent oil futures finished up nearly two percent at $71.66 a barrel after earlier reaching its highest level since July.

"Oil is extending its gains, with Brent crude back above $70 a barrel... as fears of a military confrontation between the US and Iran rattled energy markets," said Matt Britzman, senior equity analyst at Hargreaves Lansdown.

Feb 18 (Reuters) - Russian Foreign Minister Sergei Lavrov, in an interview made public on Wednesday, said that any new U.S. strike on Iran would have serious consequences and called for restraint to find a solution to enable Iran to pursue a peaceful nuclear programme.

Lavrov's interview with Saudi Arabia's Al-Arabiya television was aired a day after U.S. and Iranian negotiators held indirect talks in Geneva to head off a new mounting crisis between Washington and Tehran.

US President Donald Trump on Thursday promised $10 billion and Muslim-majority nations offered funding and troops for Gaza as he inaugurated his "Board of Peace," a new institution whose ultimate mission has drawn questions.

Trump brought together allies from around the world -- many authoritarians, with few Western democrats who traditionally ally with the United States -- to hail his peacemaking just as he sends US military might near Iran and threatens war.

WASHINGTON, Feb 18 (Reuters) - Iran is expected to submit a written proposal on how to avoid its standoff with the United States in the wake of U.S.-Iran talks in Geneva on Tuesday, a senior U.S. official told Reuters on Wednesday.

Top national security advisers met in the White House Situation Room to discuss Iran and were told all U.S. forces deployed to the region should be in place by mid-March, the official said.

Secretary of State Marco Rubio will meet Israeli Prime Minister Benjamin Netanyahu in Israel on the weekend of February 28, the official said.

Feb 18 (Reuters) - The United States is in the process of withdrawing all of its roughly 1,000 troops from Syria, the Wall Street Journal reported on Wednesday, citing three U.S. officials.

Reuters could not immediately verify the report.

Last week, the U.S. military said it completed a withdrawal from a strategic base in Syria, handing it over to Syrian forces, in the latest sign of strengthening U.S.-Syrian ties that could enable an even larger American drawdown.

A top UN official warned Wednesday that steps by Israel to tighten control of areas of the West Bank administered by the Palestinian Authority amount to "gradual de facto annexation."

Since last week, Israel has approved a series of initiatives backed by far-right ministers to consolidate control over the West Bank where the Palestinians exercise limited autonomy under past deals.