Russia seemingly has ignored Secretary of State John Kerry’s appeals to stop bombing civilians and allow critical humanitarian aid to starving Syrians – and is instead escalating its military involvement, deploying four of its most capable fighter jets to Syria, two defense officials confirmed to Fox News.

The decision to send the Su-35S jets poses yet another hurdle for Kerry’s efforts to proceed with peace talks. The Su-35S is Russia’s most advanced warplane, capable of air-to-air and air-to-ground missions, one official familiar with the jet said.

Already, continued Russian airstrikes against Syrian opposition fighters, some backed by the CIA, were enough to derail proposed peace talks in Geneva Wednesday.

Despite backing two U.N. resolutions in support of a ceasefire, Russia reneged on its promise to stop bombing civilians in Syria, a prerequisite for the U.N.-backed talks in Geneva.

“[T]here will be a ceasefire,” Kerry predicted Tuesday in Rome. “We expect a ceasefire. And we expect adherence to the ceasefire. And we expect full humanitarian access.”

Two days later, the Russian bombing hasn’t stopped and thousands of Syrians remain starving.

Syria talks to test if Assad can negotiate in good faith

Read Next: Syria talks to test if Assad can negotiate in good faith

Kerry said he was assured by his Russian counterpart the Russians would stop bombing.

“I talked to Foreign Minister Lavrov a couple of days ago and I specifically discussed a ceasefire with him, and he said they are prepared to have a ceasefire,” Kerry said.

But Kerry’s counterpart responded the next day saying the strikes would continue.

“Russian strikes will not cease [in Syria] … I don’t see why these airstrikes should be stopped,” Russian Foreign Minister Sergei Lavrov said Wednesday in Oman. Hours later, the U.N. talks fell apart.

Kerry continued calling on Russia to stop bombing Thursday in London.

“It could not be more clear. That is an obligation that is not tied to talks. It is an obligation accepted by all parties in the United Nations resolution. Russia voted for that, Russia has a responsibility, as do all parties, to live up to it,” he said.

The Russians have carried out 270 airstrikes since Monday, according to its defense ministry.

On Wednesday, a United Nations special envoy suspended the peace talks, which include participation from Russia and Iran, just hours after they began.

“It is not the end and it is not a failure of the talks,” said U.N. Special Envoy to Syria Staffan di Mistura.

US offering Russia military pact in Syria

Read Next: US offering Russia military pact in Syria

The State Department denied the peace conference was a waste of time.

“It’s not a charade because they were there and because there was a beginning,” State Department spokesman John Kirby said Wednesday.

The top U.S. general in Iraq said the U.S. wants to avoid a confrontation with Russia, despite Russia bombing U.S.-backed rebels.

“I wouldn’t characterize it as a proxy war. I would say that we are pursuing different goals,” Lt. Gen. Sean MacFarland told reporters, speaking from Baghdad earlier this week.

Meanwhile, hundreds of thousands of Syrians are starving inside the country, besieged by Russian airstrikes preventing humanitarian aid from reaching them.

The U.N. chief humanitarian coordinator says close to 500,000 Syrians are cut off from food assistance surrounded by Bashar Assad’s forces. Fifty-one people have died of hunger in Madaya, a town of 20,000, located an hour outside Damascus and just 10 miles from Lebanon and 40 miles from the Israeli border.

Aid workers who arrived with the first and only food convoy last month said they have never seen such devastation.

Read more at Fox News