By — PBS News Hour PBS News Hour Leave your feedback Share Copy URL https://www.pbs.org/newshour/show/syria-aptn Email Facebook Twitter LinkedIn Pinterest Tumblr Share on Facebook Share on Twitter Transcript Audio As the Islamic State gains more ground in Syria, President Bashar al-Assad has increasingly turned to Russia for support. Videos on social media in recent days appear to show Russian military presence in that country, causing concern in the U.S. But the Russian foreign minister would not confirm that Russians are involved in actual combat. Gwen Ifill reports. Read the Full Transcript Notice: Transcripts are machine and human generated and lightly edited for accuracy. They may contain errors. GWEN IFILL: The U.S. military reported today that U.S. airstrikes in Northeast Syria Wednesday destroyed three Islamic State fighting positions. But the U.S. effort may be getting more complicated, as Moscow steps up its support for beleaguered Syrian President Bashar al-Assad.As momentum in the Syrian war has shifted to Islamic State militants and other extremists, government forces have suffered one major blow after another. Today, ISIS forces closed in on a military base in northeastern Deir el-Zour province, the government's last major outpost there. And to the northwest, al Qaeda-linked rebels and others drove the Syrian military out of Idlib province this week.Amid those setbacks, President Bashar al-Assad has increasingly turned to Russia for support. Amateur video and images posted on social media in recent days appear to show the beginnings of a Russian military buildup. Foreign Minister Sergei Lavrov confirmed today that Moscow has sent advisers and weapons, but he would not confirm Russian forces are involved in actual combat. SERGEI LAVROV, Foreign Minister, Russia (through interpreter): Russian military personnel are present in Syria. They have been there for many years. Their presence is connected with weapon supplies for the Syrian army. The Russian military presence is there to help Syrians become familiar with this equipment. GWEN IFILL: Others are worried. Israel's defense minister said the Russians have dispatched an active force and are building an air base in Western Syria to launch strikes against Islamic State targets.And in Washington yesterday, Secretary of State John Kerry raised the issues in a phone call with Lavrov. JOHN KIRBY, State Department Spokesman: He reiterated our concern about these reports of Russian military activities or buildup, if you will, in Syria, and made very clear our view that, if true and if borne out, those reports would be — could lead to greater violence and more — even more instability in Syria. GWEN IFILL: U.S. officials say Russian airstrikes could interfere with a year-old American air campaign against ISIS, which is also designed to help moderate Syrians. Listen to this Segment Watch Watch the Full Episode PBS NewsHour from Sep 10, 2015 By — PBS News Hour PBS News Hour