The Red Cross on Thursday suspended most of its projects in Pakistan and recalled all foreign staff to Islamabad following the brutal murder of a British aid worker in the restive Balochistan province.
The International Committee of the Red Cross had frozen operations in Balochistan after the murder.
The ICRC said it had now suspended activities carried out from offices in the northwestern city of Peshawar and the southern port city of Karachi as it reviewed its "presence and activities in Pakistan".
The review was initiated following the brutal murder of Khalil Rasjed Dale, a health programme manager working for the ICRC, the organisation said in a statement.
The beheaded body of 60-year-old Dale was found by police in Quetta, the capital of Balochistan, on April 29.
"The recent attack against the ICRC compels us to completely reassess the balance between the humanitarian impact of our activities and the risks faced by our staff," said Jacques de Maio, ICRC's head of operations for South Asia.
Some of the foreign staff recalled to Islamabad will work on the review process while the majority of local staff in Karachi, Quetta and Peshawar will go on paid leave, ICRC said.
"We are currently analysing the situation and the environment with a view to setting out a clear and sustainable way forward. In the coming weeks, the ICRC will announce a decision on its future presence and set-up in Pakistan," said Paul Castella, head of the ICRC delegation in Pakistan.
"We are painfully aware that these measures are having a severe and far-reaching impact on wounded, sick, physically disabled and other vulnerable people," said Castella.
Dale, a Yemen-born British national, was kidnapped by unidentified gunmen in Quetta on January 5 while on his way home from work.