ADDIS ABABA, Ethiopia — Astebeha Tesfaye went to visit friends in Eritrea, and had to stay 20 years.
“I was going to take the bus the next day,” he said by phone on Tuesday, “but I heard that the roads were blocked, and that no one was going to move either to Eritrea or Ethiopia.”
Mr. Tesfaye was traveling as war broke out between Ethiopia and Eritrea, locking the two countries in hostilities that eventually left tens of thousands dead. Cross-border phone calls were banned, embassies were closed and flights were canceled. Travel between the countries became impossible.
But on Tuesday, the leaders of Ethiopia and Eritrea reopened crossing points on their shared border, clearing the way for trade between the two nations. The development was part of a series of reconciliation moves that began in July, when Prime Minister Abiy Ahmed of Ethiopia and President Isaias Afwerki of Eritrea signed a formal declaration of peace.
Fitsum Arega, Mr. Abiy’s chief of staff, said on Twitter that the reopening of border crossings had created “a frontier of peace & friendship.”
Mr. Abiy and Mr. Isaias visited the Debay Sima-Burre border crossing with members of their countries’ armed forces to observe the Ethiopian new year. They then did the same at the Serha-Zalambesa crossing, the Eritrean information minister, Yemane Meskel, said on Twitter.
Photographs posted online by Mr. Arega and Mr. Meskel showed the two leaders walking side by side, passing soldiers and civilians who waved the countries’ flags. In a ceremony broadcast live on Ethiopian television, long-separated families held tearful reunions. People from both sides ran toward one another as the border crossings opened, hugging, kissing and crying as if in a coordinated act.
“This must be how the people during World War I or World War II felt when they met their families after years of separation and uncertainty,” said Mr. Tesfaye, who is from a border town but was caught on the wrong side of the frontier during the war.
Eritrea gained its independence from Ethiopia in the early 1990s, and war broke out later that decade, locking the two nations in unyielding hostilities that left more than 80,000 people dead. The turning point came in June,when Mr. Abiy announced that Ethiopia would “fully accept and implement” a peace agreement that was signed in 2000 but never honored. The formal deal was signed weeks later.
Few people expected such a quick turn of events. Embassies have reopened, telephone lines have been restored and commercial flights between the capitals have resumed. An Ethiopian commercial ship docked in an Eritrean port last Wednesday — the first to do so in more than two decades.
Ethiopia has a strategic interest in a critical Eritrean port, Assab, as a gateway to international trade via the Red Sea. Landlocked since Eritrea gained independence, Ethiopia sends 90 percent of its foreign trade through Djibouti.
Bus routes through Zalambesa are expected to start soon, helping residents to move freely for the first time in decades.
Mr. Tesfaye, for one, is thrilled.
“There wasn’t any day that went by that I didn’t think of my mother,” he said, choking up. “I never thought this day would come.”