* Russians say deal close
* Obama says "grave differences" remain
* U.S. envoy's letter to opposition lays out draft deal
* Aleppo clashes, separate Turkey offensive continue
By Roberta Rampton and John Davison
HANGZHOU, China/BEIRUT, Sept 4 The United States
and Russia on Sunday tried to finalise a ceasefire deal for
Syria, a second this year after a first collapsed, but U.S.
President Barack Obama said "grave differences" remained and
fighting on the ground continued.
A truce brokered by the Cold War foes in February broke down
and peace talks between the Syrian government and opposition
ended earlier this year with both sides trading the blame.
Fighting in the five-year conflict has since escalated in many
areas, especially around the embattled city of Aleppo in the
In a move separate to the fight between the Syrian
government and its opponents, Turkey recently launched its first
full-scale incursion into Syria since the civil war began,
supporting rebels fighting Islamic State and Kurdish forces.
Speaking on the sidelines of the G20 summit in the Chinese
city of Hangzhou, U.S. President Barack Obama said the ceasefire
deal, which concerns the conflict between Syrian President
Bashar al-Assad and various rebels backed by regional and
Western allies, still faced obstacles.
"We're not there yet," he told reporters after a meeting
with British Prime Minister Theresa May.
"We have grave differences with the Russians in terms of
both the parties we support but also the process that is
required to bring about peace in Syria," Obama said.
Russia and the United States have backed opposing sides in
the conflict. Moscow has backed Assad and Russian warplanes have
been targeting the opposition for nearly a year, while
Washington has supported some rebel groups fighting under the
banner of the Free Syrian Army.
Russia's Deputy Foreign Minister Sergei Ryabkov, also
speaking on the sidelines of the G20, said a deal was close but
that the timing of any announcement could not be predicted.
"We are talking about most serious issues of implementing a
ceasefire," he said. "We are close to the deal ... but art of
diplomacy requires time to implementation. I can't tell you when
the agreement will be reached."
A letter from Washington's Syria envoy Michael Ratney to the
Syrian armed opposition, a copy of which was seen by Reuters,
told rebels an agreement could be announced soon, and laid out
some of the terms.
The deal would oblige Russia to prevent Syrian government
warplanes from bombing areas held by the mainstream opposition,
and would require the withdrawal of Damascus's forces from a key
supply route north of Aleppo, the letter dated Sept. 3 said.
In return, the United States would coordinate with Russia in
fighting against al Qaeda, it said, without elaborating.
The letter stressed that for the deal to take effect, rebels
would have to cooperate while guarantees were being sought that
Moscow, Syria's most powerful ally, would respect it.
The deal would focus on delivery of humanitarian supplies to
Aleppo, where recent advances by both sides have cut supplies,
power and water to nearly 2 million people in government- and
Government forces would withdraw from a key supply route
which previously led into the rebel-held east of the city and
which was cut in July. The Castello Road would become a
demilitarised zone, Ratney's letter said. Another route in
southwest Aleppo would subsequently be used for aid delivery.
The government and rebels would also be required not to
block any aid entering the city, it said.
The agreement required the Syrian government and Russia to
avoid bombing opposition-held areas - including where more
moderate insurgent groups are operating close to Jabhat Fatah
al-Sham, previously the al Qaeda-affiliated Nusra Front.
The February ceasefire deal excluded Nusra Front and Islamic
State. But Nusra Front severed ties with al Qaeda in July.
Earlier this year the opposition accused Moscow and Damascus of
using the close proximity of Nusra Front to more moderate rebel
groups as a pretext to bomb the latter.
BATTLES IN THE NORTH
Fighting in Syria has not slowed. Syrian government
warplanes heavily bombarded areas of southwestern Aleppo
recently captured by rebels on Saturday and Sunday, and there
were ground battles as government forces and allies attempted to
capture rebel-held territory, the Syrian Observatory for Human
Rebel official Zakaria Malahifji of the Fastaqim group,
which operates in Aleppo, said battles raged in the area on
To the northeast of Aleppo, Turkey-backed rebels pushed
Islamic State out of areas around the town of al-Rai near the
Turkish border, Malahifji said, on the second day of an
offensive launched from al-Rai.
Ten days Turkey launched its first full-scale incursion into
Syrian soil since the conflict began, aimed at IS and at
U.S.-backed Kurdish forces in the area, which have also been
battling the jihadists.
Ankara considers the Kurdish YPG militia a terrorist group
and is worried that YPG advances will embolden Kurdish militants
on its own soil.
(Reporting by Roberta Rampton, John Davison, Tom Miles in
Geneva, Vladimir Soldatkin in Hangzhou, Jack Stubbs in Moscow;
writing by John Davison; Editing by Raissa Kasolowsky)