Turkish Prime Minister Recep Tayyip Erdogan has said his country was changing its military rules of engagement.

Story highlights

NEW: Turkey asks NATO to consider no-fly zone, senior U.S. official says

Turkey's National Security Council says it will act against "hostile action" by Syria

Air defense systems and tanks have been moved to the border, state media says

Personnel have been arriving in military vehicles for two or three days, a villager says

Istanbul CNN  — 

Turkey said Thursday that it will act against “hostile action” by Syria as troops and tanks deployed to the border after the downing of a Turkish jet last week.

“The incident of our unarmed plane on a test and training mission being shot down by Syria on June 22, 2012 in international airspace, has been discussed in detail,” said a statement from Turkey’s National Security Council after a five-hour meeting.

“It has been stressed that Turkey will act with determination against this hostile action reserving all its rights arising from international law,” the statement said.

The military deployment along Turkey’s border with Syria is linked to rising tensions between the neighboring nations after the jet went down, a Turkish government official said Thursday.

The apparent bolstering of its border force comes only two days after Turkish Prime Minister Recep Tayyip Erdogan said his country was changing its military rules of engagement.

It now will treat a military approach toward its borders by Syria as a potential threat that “will be dealt with accordingly,” he said.

“It seems that this is an implication of what the prime minister said in his speech,” the Turkish official, who asked not to be named because he is not authorized to speak on the record, said when questioned on reports of troop movements in the border area.

A man from the border village of Guvecci, who asked not to be named for security reasons, said that personnel had been arriving for the past two or three days.

“They are coming in military vehicles. We hear that such transfers are taking place to all border stations,” he said.

Is Turkey moving toward ‘hard power’ over Syria?

Turkish state TV channel TRT gave details of military convoy movements in border areas on its website Thursday, saying trucks loaded with tanks had been moved to a military unit on the border with Syria.

“There were also air-defense systems among the military transfer of military vehicles and tanks,” it reported.

The semi-official Anatolia news agency also reported the transfer of armored vehicles to military posts in some districts of Sanliurfa and Hatay, along the border, on Wednesday.

Relations between the two countries, already strained, have worsened significantly since Syria shot down a Turkish F-4 Phantom jet on Friday. Both sides say the jet strayed into Syrian airspace, but Turkey says the incursion was accidental and quickly corrected.

Syria’s response drew sharp condemnation from NATO, but the alliance did not promise any action in response to the incident. NATO Secretary General Anders Fogh Rasmussen said Turkey did not invoke the NATO article calling for collective defense of members.

Turkey, while not seeking specific action, asked NATO members to study a range of ways a no-fly zone could potentially help the situation and ease threats, a senior U.S. official said.

It is “not clear what, if anything, will be done,” the official said.

The request was first reported by The Telegraph, which described it as a request for a “contingency plan.” The Telegraph cited a U.S. government source in saying the request took members by surprise but was now being taken back to the countries’ capitals for consideration.

For its part, the U.S. military planning includes a scenario for a no-fly zone as well as protecting chemical and biological sites, CNN has reported previously. Officials say all the scenarios would be difficult to enact and must involve large numbers of U.S. troops and extended operations.

Meanwhile, the search for the jet’s pilots continued.

Turkey’s chief of general staff said in an online statement Thursday that an area measuring 70 miles by 23 miles has been scanned, “however neither our pilots nor the wreckage of the plane have been reached so far.”

Some parts of the plane and some items belonging to the pilots have been found, however, the statement said.

Five military vessels, a plane and four search-and-rescue helicopters have been involved in the around-the-clock search since the plane was lost, it said. In addition, a navy hydrographic survey ship started a deep water search Tuesday.

A Syrian official said Wednesday that his country’s forces might have thought the Turkish jet it downed was from Israel.

“As you know, there is a country called Israel there and, as you know, this Zionism country’s planes are very similar. And because they both are from the same factory, from the U.S., maybe Syria thought it was an Israeli plane,” Syrian Information Minister Omran Al Zubi told the Turkish A Haber channel.

Speaking Tuesday in Ankara, Erdogan stressed that his country isn’t an aggressor, but will respond bluntly to threats.

“I express this at every opportunity: We never have our eyes on any country’s lands. We don’t show a hostile attitude against any country. We never threaten the security of any country,” he said in remarks aired on CNN Turk.

“We never hesitate to respond in the harshest way and do what is necessary with all our existing power, as well as with the power and inspiration that we get from our history, against hostile attitudes, attacks and threats against us.”

Syria raised the stakes Monday in the war of words over the incident.

Foreign Ministry spokesman Jihad Makdissi said the plane was shot down in Syrian airspace, disputing Turkey’s claim that it was downed over international waters after briefly straying into Syrian airspace by mistake.

“What happened was a violation of Syrian airspace. Even Turkey says Syrian sovereignty was violated. Regardless of whether it was a training mission, a reconnaissance mission, it was a violation,” Makdissi said.

Photos: In Syrian hospital, no escape from war

CNN’s Ivan Watson and Elise Labott contributed to this report.