The missile batteries were deployed after Syria's shooting down of a Turkish warplane, which has sharply raised tensions between the two nations.
They represent a graphic warning to President Bashar al Assad, coinciding with rising violence across Syria and increasingly urgent international efforts to forge a peace deal.
As the Turkish-Syrian dimension ratcheted up further pressure, peace envoy Kofi Annan said yesterday he was "optimistic" about crisis talks in Geneva today.
Regional analysts said that while neither Turkey nor its Nato allies appeared to have any appetite to enforce a formal no-fly zone over Syrian territory, Prime Minister Tayyip Erdogan had made it clear Mr Assad would be risking what he called the "wrath" of Turkey if its aircraft strayed close to its borders.
Turkey, which is sheltering some 34,000 Syrian refugees and providing bases for the rebel Free Syria Army, is at the forefront of the efforts to bring down Mr Assad. Last weekend, Damascus said "terrorists" infiltrating from Turkey were killed.
The US, Britain and France have said that Mr Assad is responsible for the violence, which the United Nations estimates has killed at least 10,000 people, and is no longer fit to govern. However, Russia and China reject what they describe as Western calls for "regime change".
Ahead of today's meeting, Russia proposed changes to Mr Annan's plan for a national unity government in Syria, despite initially supporting it, but the US, Britain and France rejected the amendments, Western diplomats said.
The British-based Syrian Observatory for Human Rights said 190 people, including 125 civilians, were killed on Thursday.
Meanwhile, Mr Assad dismissed the notion of any outside solution to the 16-month-old uprising against his rule, saying: "We will not accept any non-Syrian, non-national model, whether it comes from big countries or friendly countries. No one knows how to solve Syria's problems as well as we do."