BEIRUT — NATO is ready to defend alliance member Turkey amid artillery and mortar exchanges with Syria, its top official said Tuesday, as Ankara sent additional fighter jets to reinforce an air base close to the Syria border where tension has escalated dramatically over the past week.
Turkey and Syria have exchanged fire across their common border since errant Syrian shells killed five Turkish civilians last week, raising fears of a wider regional crisis.
The comments by NATO Secretary-General Anders Fogh Rasmussen were the strongest show of support to Ankara since the firing began Wednesday -- though the solidarity is largely symbolic.
Turkey has sought NATO backing but not direct intervention, and the alliance is thought to be reluctant to get involved militarily at a time when its main priority is the war in Afghanistan.
Ahead of a meeting of NATO defense ministers in Brussels, Mr. Fogh Rasmussen backed Turkey's right to defend itself.
"Obviously Turkey can rely on NATO solidarity," he added. "We have all necessary plans in place to protect and defend Turkey if necessary.
"We hope that all parties involved [in the Syrian crisis] will show restraint and avoid an escalation of the crisis," Mr. Fogh Rasmussen said.
NATO officials said the plans have been in place for decades and were not drawn up in response to the Syria crisis. They spoke on the condition of anonymity because they were not authorized to talk to the press.
In an address to lawmakers from the ruling party, Turkish Prime Minister Recep Tayyip Erdogan reiterated that Ankara will continue retaliating for attacks from the regime of Syrian President Bashar Assad.
"Every kind of threat to the Turkish territory and the Turkish people will find us standing against it," Mr. Erdogan said. "Soldiers loyal to Assad threw shells at us, we immediately reacted and responded with double force. We shall never stop responding."
Analysts say Syria appears to be intentionally escalating tensions along the border with Turkey to send a message to its northern neighbor that it will pay a high price for its support of the Syrian rebels, hoping that will deter any foreign military intervention in the almost-19-month-old civil war.
At least 25 additional F-16 fighter jets were deployed at Turkey's Diyarbakir air base in the southeast late Monday, Turkey's Dogan news agency said, quoting unidentified military sources. The military's chief of staff inspected troops along the border with Syria on Tuesday.
The reinforcement of the Diyarbakir base also bolsters Turkish forces along the volatile Iraqi border. Turkish jets struck Kurdish rebel targets in northern Iraq in two separate cross-border raids Sunday despite recent warnings from Baghdad against any military operations on its territory.
Turkey frequently has struck targets in northern Iraq of the Kurdistan Workers' Party, or PKK, which seeks autonomy for Turkey's Kurdish minority.
Relations between Turkey and Iraq also have been deteriorating over a Turkish decision to shelter convicted Iraq's Sunni vice president on charges of running death squads.
Activists estimate more than 32,000 people have been killed since March 2011 when the uprising against Mr. Assad's regime began.
Initially, regime opponents launched a wave of peaceful protests that were met by repeated attacks by security forces, and the conflict has gradually turned into bloody civil war that has prompted tens of thousands of civilians to flee Syria.
The fighting has devastated entire neighborhoods in Syria's main cities, including the northern city of Aleppo.
Syria's government has always blamed the uprising on what it calls foreign terrorists.