Patriot missiles deployed in Turkey since 2013 to guard against rockets from Syria will be removed for planned upgrades in October, despite the ongoing crisis across the border, the Pentagon said Thursday.

"The Patriots will be redeployed to the United States for critical modernization upgrades that will ensure our missile defense force remains capable of countering evolving global threats and protecting allies and partners -- including Turkey," Defense Department spokeswoman Laura Seal said.

The United States and Turkey had in August announced the withdrawal of the missiles, deployed under NATO authority in 2013.

Germany has also announced its intention to withdraw its two Patriot missile batteries from Turkey.

NATO can still use a Spanish missile battery that has been deployed since January in Adana in the south of Turkey.

Seal said that if needed, the United States could send the Patriot missiles and their personnel back to Turkey "within one week."

"We will also retain a persistent presence of US Navy multi-role Aegis ships in the eastern Mediterranean," she added.

The military situation in Syria is changing at a new pace, after Russia on Wednesday launched its first air strikes in the country.

Patriots can shoot down tactical ballistic weapons, cruise missiles or planes.