"He's reassured me that the ECB have got an emergency meeting on 4 August and they'll be making a decision there," said Pietersen.
Collier added: "It's a very fluid situation in Pakistan at the moment. It's primarily the external environment we're looking at and which we have raised some concerns over. We will be monitoring that very closely."
Collier said England's players would be consulted before any decision is taken.
"We're in very close touch with the PCA (Professional Cricketers Association)," he said.
"Clearly, other boards around the world are in the same position. The safety and security of our players is paramount and we won't compromise on that."
Security in Pakistan has been a matter of concern following the assassination of former Prime Minister Benazir Bhutto in December.
South Africa had armed guards for their trip to Pakistan last year
South Africa captain Graeme Smith said his players were worried, having played in Pakistan last October.
"From the players' point of view, we do have major concerns with security in Pakistan," said Smith.
"A lot has happened in Pakistan, from a security point of view, since we were there and those are things that are worrying us.
"Generally, that's a full-player view. I don't know any players who don't have issues with regards to security in Pakistan.
"There were bombings taking place in Karachi and bombings are taking place in Lahore now.
"Within three days (of us returning home), there was a state of emergency so we have seen how quickly things can develop."
Smith said Gerald Majola, chief executive of Cricket South Africa, and national players union chief Tony Irish were monitoring the situation in Pakistan.
Australia have already cancelled one trip there and could do so again.
"The risks are too great for us to recommend our players go there," said Paul Marsh, chief executive of the Australian Cricketers' Association.
You may find a world-class event that doesn't feature a large number of world-class players. That would be a real shame for cricket
Sean Morris PCA chief executive
"We would expect Cricket Australia to adopt the same position."
Australian all-rounder Andrew Symonds added: "It is only a game of cricket at the end of the day and putting yourself in a position where you're not safe is ridiculous."
The chief executive of New Zealand Cricket is also planning to speak to Heath Mills, the boss of the New Zealand Cricket Players' Association, after he said he could not advise his members to go to Pakistan.
"We believe this is a poor ICC decision. We can't see how they have put player safety as their number one priority and this is very disappointing," he stated.
"Our recommendation to our players is not to travel to Pakistan at this point in time.
"There isn't one player I have spoken to who is comfortable about travelling to Pakistan at the moment."
Sean Morris, the chief executive of the PCA, echoed the thoughts of his counterparts in Australia and New Zealand.
"We've still got some very serious concerns, despite the fact that the Pakistan Cricket Board have made every effort they can to try to make it as safe as possible," he said.
"But, unfortunately, in that part of the world there are some matters that are beyond anyone's control.
"I think one thing that the England and Wales Cricket Board has said - and something we are very well aligned on - is the one thing you are never going to compromise on is security.
"You may find a world-class event doesn't feature a large number of world-class players. That would be a real shame for cricket."
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