Colombian President Andres Pastrana, showing a new toughness, has wrested his first major concessions from leftist guerrillas in three years of peace talks, helping counter his image among Colombians as a wishy-washy leader.

A series of eleventh-hour accords, culminating Sunday with a mutual pledge to seek a cease-fire by early April, has also opened a larger international role in the country's acrimonious peace process.

The latest deal was struck after nearly two weeks of heightened troop maneuvers around the main stronghold of the Revolutionary Armed Forces of Colombia — and intense mediation by U.N. and other foreign envoys.

On Monday, U.N. Secretary-General Kofi Annan called the accord "a promising roadmap for peace talks."

The agreement propels the government and the FARC into internationally monitored negotiations for the first time since the peace process began in January 1999.

War-weary Colombians are hoping it will bring a reprieve in a 38-year-old guerrilla conflict that kills some 3,500 people annually and has driven millions from their homes.

Daniel Garcia Pena, a former government peace negotiator, called the agreement a "qualitative leap" in the peace process and said Pastrana had regained his stature in the public's eye.

"Only a few days ago, it seemed the peace process was an imposition of a fortified guerrilla group over a weak president, and I believe that has changed today," Garcia Pena said in an interview.

Horacio Serpa, the leading candidate in May's presidential elections from the opposition Liberal Party, cautioned against rejoicing until there are more tangible results. "It's the best agreement reached to this point, but it's not a panacea," Serpa said.

In Sunday's accord, signed in a rebel-held village, the FARC and the government set an April 7 deadline for coming to terms on a cease-fire.

The rebels agreed to discuss a halt to kidnappings — a major FARC income source — as part of the truce. The government, in turn, agreed to direct talks about dealing with a brutal right-wing paramilitary group supported by rogue elements in Colombia's U.S.-backed military.

The two sides also agreed to install an international commission next month that would help settle disputes and pressure both sides to comply.

"Now it won't just be the FARC's word before the government and the Colombian people, but before the international community, too," Pastrana declared.

The commission was expected to include some of the same people who helped salvage negotiations in recent days — ambassadors from 10 nations acting as "friends" to the process and U.N. envoy James LeMoyne, who helped lubricate one session by exchanging bottles of aged whiskey with the FARC.

Setting up a workable cease-fire will be complicated.

Dozens of guerrilla fronts are scattered around the country, and FARC's full control over all of its 16,000-strong army has been questioned. Rebels could consider any actions taken by the paramilitaries to be violations by the government. The last government-FARC truce, in place between 1983 and 1987, was violated repeatedly.

The U.S. government, while declining a direct role in peace talks because it considers the FARC a terrorist group, said Sunday it will continue to support Pastrana's peace efforts.

Washington is also providing weaponry and training to the Colombian military for counterdrug activities. U.S. officials have reportedly been weighing more direct counterinsurgency support.

Pastrana's critics have labeled him weak. The president ceded the FARC a territory twice the size of New Jersey at the outset of the talks and has repeatedly renewed the zone despite a lack of progress and growing pressure to clamp down on rebel criminal activities in the area.

Two weeks ago, Pastrana abruptly hardened his line — moving thousands of troops onto the edge of the zone and threatening an attack unless the guerrillas made concessions. The FARC capitulated, returning to the talks they had left in October and then signing Sunday's accord. Pastrana, in turn, has extended the zone again through Apr. 10.

"Pastrana wants to be remembered as somebody who gave all he could for peace, but was willing to get tough when the other side did not reciprocate," said Michael Shifter, an analyst at the Inter-American Dialogue in Washington.