"Iran is closely monitoring the alarming violence in Nagorno-Karabakh," Zarif tweeted on Sunday.
"We call for an immediate end to hostilities and urge dialogue to resolve differences.
"Our neighbors are our priority and we are ready to provide good offices to enable talks.
"Our region needs peace now."
According to reports coming from the region, clashes erupted between Azerbaijan and Armenia on Sunday over the volatile Nagorno-Karabakh region, reigniting concern about instability in the South Caucasus, a corridor for pipelines transporting oil and gas to world markets.
Both sides, which fought a war in the 1990s, reported fatalities. Armenia and Nagorno-Karabakh, a breakaway region that is inside Azerbaijan but is run by ethnic Armenians, declared martial law and mobilized their male populations.
Iran called on Azerbaijan and Armenia to exercise restraint and engage in negotiations.
“The Islamic Republic of Iran is closely monitoring military conflicts between the Republic of Azerbaijan and the Republic of Armenia with concern, and while inviting both parties to show self-restraint, calls for immediate cessation of clashes and initiation of talks between the two countries,” Iranian Foreign Ministry spokesman Saeed Khatibzadeh said on Sunday.
He added that Tehran is ready to employ all its capacities to help establish a cease-fire and start peace talks between the two sides.
Nagorno-Karabakh broke away from Azerbaijan in a conflict that broke out as the Soviet Union collapsed in 1991.
At least 200 people were killed in a flare of the conflict between Armenia and Azerbaijan in April 2016. There are frequent skirmishes and at least 16 were reported killed in clashes in July.