The Syrian armed forces have been conducting "large-scale" manoeuvres to test their "combat capability and readiness", Syrian state media report.
The exercises showed Syria was able "to defend [its] shores against any possible aggression", according to state-run news agency Sana.
Tensions along the border with Turkey have been raised after Syria shot down a Turkish fighter jet last month.
Meanwhile President Assad has accused the US of trying to destabilise Syria.
He said in an interview with German broadcaster ARD that the US was "part of the conflict" and was giving political support to "gangs" trying to "destabilise" his country.
The remarks were provided by the station ahead of the transmission of the interview later on Sunday.
Syrian Defence Minister Gen Dawoud Rajha was one of several high-ranking officers attending the manoeuvres, according to a report on Syrian TV.
"Our Navy forces started to conduct an operational tactical manoeuvre with live ammunition, during which naval and coastal rockets were fired," the report added.
The exercises were part of a training plan which involves manoeuvres "carried out over several days", Sana said.
Some in the Syrian opposition have called for foreign military intervention to unseat Mr Assad's government.
Last week Turkey scrambled six F-16 fighter jets near its border with Syria after Syrian helicopters came close to the border.
Also last week, Turkey said it had begun deploying rocket launchers and anti-aircraft guns along the border in response to the downing of its F-4 Phantom jet on 22 June.
Syria said the Turkish F-4 was shot down by air defence fire inside its airspace.
Meanwhile, violence continued in Syria on Sunday with 11 people reported dead, according to the Local Co-ordination Committees (LCC), a network of activists inside Syria.
Three of the dead were soldiers who had defected, the LCC said.
Over 15,000 people are thought to have been killed since the start of the anti-government uprising more than a year ago.
UN-Arab League envoy Kofi Annan has arrived in Damascus.
Mr Annan will hold talks with President Bashar al-Assad, his office said.
On Saturday Mr Annan said his six-point peace plan for Syria had so far "failed", in comments to French newspaper Le Monde.
Recent diplomatic moves by world powers to try and reach agreement on Syria have also not resulted in fresh action.
Earlier this week, a group of more than 100 countries known as the Friends of Syria called on the UN Security Council to adopt Mr Annan's six point plan under Chapter 7 of the UN Charter, which would allow for further sanctions.
However, Russia and China, both of whom hold vetoes at the Council, were not at the meeting and have refused to call for Mr Assad's departure - a key demand of many in the Syrian opposition.