Siniora asked UN peacekeepers tasked with monitoring the border, "to be careful" that Israel will not use the maneuvers "to launch operations capable of increasing tension," a statement from his office said.
He also urged the Lebanese army to "be extremely vigilant and take the necessary measures to protect Lebanese civilians and face up to any Israeli violation" of Lebanese territory.
Siniora expressed concern that Israel could violate the terms of UN Security Council Resolution 1701 which was adopted to end the month-long war between the Shiite militant group Hizbullah and Israel in south Lebanon in 2006.
'Syria is ready to defense itself'
According to Siniora's office, General Claudio Graziano, the commander of the United Nations Interim Force in Lebanon (UNIFIL), informed the Lebanese army that Israel was planning "unprecedented and massive military maneuvers on April 6."
Israeli media have reported that the Jewish state will hold from Sunday a large-scale home front defense exercise featuring scenarios in which chemical and biological missiles hit populated areas.
Lebanese daily As-Safir quoted diplomatic sources in New York as saying that Israel has asked UNIFIL to inform the Lebanese government that the military exercise will not threaten Lebanon or Hizbullah and that "it will not include the border region".
UNIFIL officials told the newspaper that both the Lebanese army and Hizbullah have raised their alert level ahead of the exercise.
Referring to the planned Israeli military exercise, Syrian Foreign Minister Walid Moallem said Thursday that his country has chosen peace as a strategic choice, but must remain alert in case of any act of aggression on Israel's part.
"Syria is ready to defense itself against any aggressiveness," he told European Union ambassadors during a dinner in Damascus, the London-based Arabic-language newspaper al-Hayat reported.
The newspaper said that Israel and Syria have exchanged peaceful messages on the backdrop of recent reports of tension.