* G7 leaders to hold two days of talks in Sicily
* Allies want Trump to endorse Paris Agreement
* UK suicide attack casts cloud, puts focus on security
By Crispian Balmer and Noah Barkin
TAORMINA, Italy, May 26 (Reuters) - U.S. President Donald Trump will face pressure at his first summit of major industrialised nations on Friday from allies eager to promote free trade and safeguard international accords on climate change.
The annual Group of Seven (G7) meeting is being held in a chic Sicilian resort town, with Europe's most active volcano, Mount Etna, gently smoking in the background and the Mediterranean Sea gleaming beneath the cliffs.
Hosts Italy hope the luxurious, relaxed surroundings will give the rich-nation leaders a rare chance for wide-ranging debate on an array of international issues, including Syria, North Korea and the global economy.
They will also discuss security cooperation following Monday's suicide bombing at a concert in northern England that killed 22 people and was allegedly carried out by a young Islamist militant of Libyan descent who grew up in Britain.
A senior Italian diplomat said Trump and the heads of Britain, Germany, France, Italy, Japan and Canada saw eye-to-eye on many issues ahead of the two-day summit, but Washington remained isolated on commerce and the environment.
European Union nations are eager for a clear U.S. pledge "to fight all forms of protectionism", said the diplomat, who declined to be named. But they were struggling to convince the U.S. president of the merits of free trade.
"We will have a very robust discussion on trade and we will be talking about what free and open means," White House economic adviser Gary Cohn told reporters late Thursday.
He also predicted "fairly robust" talks on whether Trump should honour a U.S. commitment to cut greenhouse gas emissions under the 2015 Paris Agreement.
He said the president, who has dismissed global warming as a "hoax", would make a final decision when he returned home, but stressed that he would put economic development first.
Even if a decision is not forthcoming, European diplomats expect their leaders to push Trump hard on the Paris emissions deal, which has comprehensive support across the continent.
"This is the first real opportunity that the international community has to force the American administration to begin to show its hand, particularly on environment policy," said Tristen Naylor, a lecturer on development at the University of Oxford and deputy director of the G20 Research Group.
Trump, on the final leg of a nine-day tour of the Middle East and Europe, arrived in Sicily late Thursday after publicly criticising partners in Brussels for what he called their "chronic underpayments" to the NATO military alliance.
He will not be the only G7 newcomer. French President Emmanuel Macron, Italian Prime Minister Paolo Gentiloni and British Prime Minister Theresa May will also be attending the elite club for the first time, although May is expected to leave a day early because of the Manchester bombing.
Italy chose to stage the summit in Sicily to draw attention to Africa, which is 140 miles (225 km) from the island at its closest point across the Mediterranean.
More than half a million migrants, most from sub-Saharan Africa, have reached Italy by boat since 2014, taking advantage of the chaos in Libya to launch their perilous crossings.
Italy is eager for wealthy nations to do much more to help develop Africa's economy and make it more appealing for youngsters to stay in their home countries.
The leaders of Tunisia, Ethiopia, Niger, Nigeria and Kenya will join the discussions on Saturday to say what should be done to encourage investment and innovation on their continent.
One country that won't be present is Russia. It was expelled from the group in 2014 following its annexation of Crimea from Ukraine.
Trump called for improved ties with Moscow during his election campaign.
But accusations from U.S. intelligence agencies that Russia intervened in the U.S. election to help Trump and investigations into his campaign's contacts with Russian officials have hung over his four-month-old presidency and prevented him from getting too close to Moscow.
Trump has largely stuck to script and kept his tweeting to a minimum on a trip which has taken him to Saudi Arabia, Israel, the Palestinian territories, the Vatican and Brussels. He is not expected to hold a news conference in Sicily before returning to Washington on Saturday. (Additional reporting by Steve Holland; Editing by Hugh Lawson)