Donald Trump has spent much of his first year as president of the United States seeking to undo the legacy of his predecessor, Barack Obama.

The volatile Middle East is one of the many areas where Trump has broken with US policy and precedent.

On Wednesday, Trump overturned decades of US policy by announcing that Washington recognizes Jerusalem as the capital of Israel and setting in motion plans to move the embassy there from Tel Aviv.

Here is a look at some of the hot button issues in the Middle East and the new course being steered by Trump:

- Israel and the Palestinians -

Trump has instituted a policy of unwavering support for Israel after a period of strained relations between Obama and Prime Minister Benjamin Netanyahu.

The last days of the Obama administration included an extraordinary US refusal at the United Nations to block a Security Council resolution condemning Israeli settlement construction.

Netanyahu welcomed Trump's November 2016 election saying he was a "true friend of the State of Israel."

Since then, Trump has appointed a US ambassador to Israel, David Friedman, known for his support for settlement activity, and ordered the withdrawal of US support for UNESCO, citing anti-Israel bias.

Trump has tasked his son-in-law Jared Kushner, a senior adviser, with relaunching moribund peace talks between Israel and the Palestinians.

But he has been lukewarm about a Palestinian state and angered Palestinian leaders earlier this year with a threat -- since withdrawn -- to close the Palestine Liberation Organization mission in Washington.

- Iran -

Trump considers Iran to be the principal threat to US interests in the Middle East and has frequently condemned the Islamic Republic for what he sees as its "destabilizing" influence in Yemen, Syria and Lebanon.

Trump has been a relentless critic of the Iran nuclear deal signed in 2015 and has repeatedly threatened to scrap the agreement intended to prevent Tehran from developing nuclear weapons.

The president's tough stance on Iran has earned praise from Netanyahu and from Saudi Arabia, the Islamic Republic's chief regional rival.

- Saudi Arabia, Egypt -

Trump has strengthened ties with Saudi Arabia and his first official visit abroad as president was to the oil-rich monarchy, where he was received with pomp and circumstance.

Trump threw his support behind the anti-corruption crackdown launched by Saudi Crown Prince Mohammed bin Salman and Saudi actions against Qatar, which Riyadh accuses of cooperating with Tehran.

Relations with another Middle East powerhouse -- Egypt -- have also entered a new era under Trump.

Egyptian President Abdel Fattah al-Sisi was persona non grata under Obama and the United States cut off some military aid because of the bloody crackdown on supporters of the former president.

But Trump welcomed Sisi to the White House in April and proclaimed his "strong backing" for the Egyptian leader.

- Syria -

Trump frequently accused Obama of failing to stand up to Syrian President Bashar al-Assad and in April he ordered the first US military strike on Syrian troops since the civil war began in that country.

Dozens of US missiles were fired at a Syrian air base in retaliation for a chemical weapons attack on a rebel town which left 87 people dead.

The United States has deployed some 2,000 troops in Syria and the Pentagon said Tuesday that they will stay "as long as we need" to prevent a return of the Islamic State group.

Trump also reinforced the US military contingent in Afghanistan, a move at odds with Obama's efforts to withdraw US troops from conflict zones abroad.