Russia's ambassador to Lebanon Alexander Zasypkin said any missiles fired at Syria would be shot down and the launching sites targeted.

The U.S. military was ready to provide military options, if appropriate, he added.

Since coming to office Trump has thumbed his nose at domestic opposition, brushed aside Moscow's actions in the United States, Ukraine and Syria and embraced tighter relations with the Kremlin.

Netanyahu and President Donald Trump reportedly also had a tense exchange last week regarding Syria after Trump pledged to wind down USA involvement in the country.

Putin told the foreign envoys that Russian Federation was ready to hear their constructive initiatives and use them as basis for better ties with other nations. Any U.S. strike would probably involve the navy, given the risk to aircraft from Russian and Syrian air defences.

'How many battleships does the U.S. and North Atlantic Treaty Organisation have in the Mediterranean compared to Russian Federation. A USA guided-missile destroyer, the USS Donald Cook, is in the Mediterranean.

"Upon an initiative of the Israeli side, a telephone conversation took place between Russian President Vladimir Putin and Israeli Prime Minister Benjamin Netanyahu", Sputnik, a Russian government-owned news agency, reported Wednesday, quoting the Kremlin.

The WHO cautioned that it has no formal role in forensic inquiries into the use of chemical weapons.

After Russia warned the United States against military strikes in Syria, President Donald Trump says missiles "will be coming".

While no solid evidence that the purported chemical attack has emerged, top U.S. officials have squarely pinned the blame for it on Damascus.

Trump fired-back at the Kremlin's claim that the Russian military was prepared to "shoot down" any USA or coalition airstrikes aimed at the Syrian regime; telling Putin that American missiles were on their way.

His remarks were part of a series of early-morning tweets regarding rising tensions between Russian Federation and Syria and the United States.

Earlier on Wednesday, Russian President Vladimir Putin urged Netanyahu in a phone conversation to do nothing to destabilise Syria. This will be caused by an unannounced air strike on Syria using stealth bombers.

Earlier, a spokeswoman for the Russian Foreign Ministry responded to Trump on Facebook, saying missiles would destroy "all evidence" of the attack.

"The Prime Minister reiterated that Israel will not allow Iran to establish a military presence in Syria", the statement said without noting who initiated the call.

Last year, the United States carried out strikes from two Navy destroyers against a Syrian air base after another toxic gas attack on a rebel-controlled pocket.