UK Defense Secretary Michael Fallon told the House of Commons that while good progress was being made against the militant group in Iraq, the situation in Syria was "complicated" due to cooperation between rebel fighters and the Syrian government.
"Daesh are being pushed back in Iraq, there's no doubt about that — they're being pushed up the Tigris and they're being pushed back West along the Euphrates," he told MPs.
Fallon said Daesh was "on the back foot in Iraq" but that "that is not happening yet in Syria and I… am extremely concerned about the proliferation of Daesh along the Libyan coastline."
UK: Kurdish Cooperation With Damascus 'Disturbing'
Fallon's comments echo the sentiment of British Foreign Minister Philip Hammond, who last week attracted criticism when he said there was "very disturbing evidence" of cooperation between armed Kurdish groups, the Syrian government and Russian forces in northern Syria.
"What we have seen over the last weeks is very disturbing evidence of coordination between Syrian Kurdish forces, the Syrian regime and the Russian air force which are making us distinctly uneasy about the Kurds' role in all of this," Hammond said.
Hammond was heavily criticized for his comments, with critics pointing out that the Kurds have been one of the West's most effective and valuable allies on the ground in Syria and Iraq, who have worked alongside the US-led international coalition, as well as Russian and Syrian government forces.
Impact of British Airstrikes Limited
The admission that British intervention was not having a significant impact on Daesh in Syria has added further embarrassment to the UK, after Prime Minister David Cameron declared in December that an extension of airstrikes against Daesh in Syria would "cut off the snake's head."
Despite claims the UK's intervention could be a game changer in the fight against Daesh in Syria, a Freedom of Information (FoI) request from the Huffington Post in February revealed only seven militants from the group had been killed by British bombs.
The latest revelation also seemed to justify the stance of UK opposition leader Jeremy Corbyn, who campaign against the UK bombing targets in Syria, saying it would amount to another "reckless, half-baked intervention."
During the House of Commons debate in December, Corbyn said Cameron had not made the case that British intervention would have a significant impact on events in Syria, given airstrikes were already being undertaken by the US, Russia, France and others.
"Whether it's the lack of a strategy worth the name, the absence of credible ground troops, the missing diplomatic plan for a Syrian settlement, the failure to address the impact on the terrorist threat or the refugee crisis and civilian casualties: it's become increasingly clear that the prime minister's proposals for military action simply do not stack up."