Asked if the attacks would affect the UN-sponsored talks, Staffan de Mistura said: "I hope not, but it was tragic."
He added "every time we are having talks or negotiations there is always someone who tries to spoil. We were expecting that."
The suicide assaults on two security service bases in Syria's third city of Homs killed dozens of people, including a top intelligence chief, overshadowing the Geneva talks.
Syria's former Al-Qaeda affiliate Fateh al-Sham Front claimed the spectacular attack which targeted and killed General Hassan Daabul, a close confidant of President Bashar al-Assad.
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Provincial governor Talal Barazi said 30 people were killed and 24 wounded.
The UN envoy was speaking as he prepared for more separate meetings with Syrian regime and opposition negotiators in Geneva, seeking to kickstart a new round of peace talks.
At the last such UN-sponsored talks the two sides did not meet for face-to-face negotiations, with de Mistura shuttling between them as a mediator.
The veteran UN diplomat said yesterday that he would ideally like to get them to talk directly, but acknowledged that there were difficulties in achieving that.