Colombia's talks with Revolutionary Armed Forces of Colombia rebel group are faltering amid hardening positions on both sides after two months of a bizarre truce.

FARC announced last Sunday an end to its unilateral cease-fire and dismissed government calls for a fast-track peace settlement. Senior government aides of President Juan Manuel Santos say FARC never stopped attacking government and public targets during the truce, which coincided with peace talks in Cuba.

Likewise, Santos kept up military pressure on FARC with frequent operations as his aides and FARC leaders sat in Havana talking of a peace settlement.

Santos said he would put any peace settlement to a public vote before implementing it. He also ruled out a halt to government military operations against FARC suspects until a deal was signed.

Putting a peace pact to public vote means the government will continue operations for the foreseeable future, analysts said. FARC's end of truce warning put government forces on high alert, as FARC has been blamed for urban terrorism, jungle firefights and ambushes, including raids allegedly perpetrated while the two sides were in peace negotiations.

FARC declared the unilateral cease-fire when the talks began in November but Colombia's ombudsman cited 57 attacks during the 50-day truce. Independent confirmation linking violent incidents and FARC hasn't been available.

FARC lead negotiator Ivan Marquez -- the name is said to be pseudonym -- said the group was ending the unilateral truce "with pain in our heart," Colombia Reports said.

The government's plans for dealing with other rebel groups in the country remain on the back burner. Amid talk of integrating FARC into the political mainstream, the future of government ties with those groups remains important.

Several groups have rejected peace talks with the government, indicating they may seek to disrupt any FARC-Santos peace deal, analysts said.

The government says it is prepared for a surge in rebel violence. Analysts say Santos may be seeking to buy time on one of FARC's key demands on land redistribution.

FARC wants more rights for Colombia's poor and wants up to one-fourth of the land distributed among poor farmers. FARC hopes to capitalize on any government concession on the issue.

The Santos administration, in the meantime, wants to remain on the good side of Colombia's rich land owners and wealthy business classes.

Another stumbling block is FARC's demand for enshrining any accord in a revised constitution. FARC says it wants assurances the government won't renege on agreements.

FARC has fought successive Bogota governments since 1964 and has been blamed for tens of thousands of casualties but now seeks to join a political process that grants its activists amnesty and opportunities in government power sharing.

"It's very possible that we could find a way to seek popular approval for any accord," Santos said during a public address. "That's still to be discussed."

Santos has ruled out talks with FARC on major changes to Colombia's economic or political model, saying such changes should come after FARC activists integrate into the political process. FARC wants any peace deal built into a revised constitution, an argument Santos has rejected so far.