ANKARA/MOSCOW: Turkey recovered the body of a Russian pilot from northern Syria and presented it to Russian diplomats Sunday, five days after shooting down his warplane in an incident that wrecked relations between two of the main powers involved in Syria’s war. A coffin carrying Oleg Peshkov arrived by ambulance on the tarmac of Hatay Airport in southern Turkey near the Syrian border, a Reuters photographer said.

It was flown to the capital Ankara, where according to Russia’s RIA news agency it was met at an airfield by Moscow’s ambassador and military attaché. The Russian Embassy declined to comment and Turkish officials did not immediately disclose when the body would be repatriated to Russia.

The shooting down of the Russian fighter jet by NATO-member Turkey has set back efforts to forge a united front against ISIS in the weeks since militant group claimed responsibility for mass killings in Paris and blowing up a Russian airliner.

Moscow has responded toward Ankara with fury, calling the episode a preplanned provocation. President Vladimir Putin signed a decree Saturday imposing punitive economic sanctions against Turkey. Details of Turkish goods that will be banned and other measures under the decree are expected to be announced in coming days.

Since the downing of the plane, Moscow has ramped up airstrikes against rebels in Syria near the Turkish border.

Turkey says it shot down Peshkov’s plane in its airspace after it ignored repeated warnings. Russia says it was flying over Syria and was struck unprovoked. The navigator of the two-seat jet survived but a second Russian service member was killed rescuing him from northern Syria.

Turkish Prime Minister Ahmet Davutgolu said Sunday that Peshkov’s body had arrived in Turkey overnight, but gave no further details of how it was recovered or brought across the border.

Turkey is part of a coalition of countries led by the United States that have been bombing ISIS positions in both Syria and Iraq, while also calling for Syrian President Bashar Assad to step down.

Russia, which supports Assad, launched its own separate bombing campaign against Assad’s opponents nearly two months ago.

Davutoglu called for more military cooperation: “Communication and coordination in Syria operations is needed in order to prevent further incidents, because two different coalition groups are conducting operations in Syrian air space always risk leading to similar incidents,” he said before getting on a plane to Brussels for a meeting on the migrant crisis with EU leaders. He also accused Russia of using anti-ISIS operations as a pretext to help Assad.

Turkey is a major customer of Russian natural gas exports and a big destination for Russian tourists. Russia buys Turkish exports including produce, having already banned food from the United States and European Union in retaliation for financial sanctions imposed over Moscow’s intervention in Ukraine.

Russia’s Sports Minister Vitaly Mutko said Sunday Moscow would not boycott international sporting events held in Turkey, but would require maximum security and would limit training trips by Russian athletes there, RIA reported.

Turkey has been angered by the Russian military campaign in Syria, complaining in particular in recent weeks about Moscow’s targeting of ethnic Turkmen rebels in the border area, who are close kin with Turks.

Pro-government newspaper Sabah Daily reported that Turkey had tightened security along its border with Syria Saturday, deploying additional tanks, armored personnel vehicles and other weapons alongside its border with Syria. A Turkish official said he could not confirm this.

Syrian State news agency, SANA, quoted Assad as telling a senior Iranian official Sunday that his enemies had increased funding and weapons supplies to insurgents.

Assad made his comments during a meeting Sunday with Ali Akbar Velayati, a top adviser to Iran’s Supreme Leader Ayatollah Ali Khamenei, who arrived in Damascus earlier in the day.

Assad spoke of “important gains by the Syrian army in the fight against terrorism, with the support of its friends led by Iran and Russia.”

He was also quoted as saying that these gains had “pushed certain countries hostile to Syria and who pretend to fight terrorism to ... increase their financing and arming of terrorist groups.”

Assad did not identify any country by name but since the outbreak of the Syrian conflict in March 2011, he has accused Turkey and Gulf nations of arming his mainly Sunni opponents.

Assad’s regime launched a key offensive to retake areas seized by opponents after Russia began its military campaign in Syria.

The latest developments came as Britain pressed efforts to widen its participation in a U.S.-led air coalition battling ISIS in Iraq to also include Syria.

Defense Secretary Michael Fallon said his government was intensively lobbying the opposition Labour party to support airstrikes in Syria, two years after it had blocked that option, but the government had “not yet” secured enough support to be sure of winning such a vote.

Following the Nov. 13 Paris attacks, there have been increasing calls by French leaders on their allies to step up the fight against ISIS.

Thursday French Defense Minister Jean-Yves Le Drian called on Britain to help “win this war.”

British Prime Minister David Cameron said Saturday that ISIS was a threat to Britain and conducting air strikes in Syria would be the “right thing for Britain to do.”

He was speaking as thousands of people took to the streets of London to protest against military action in Syria.