Pope Francis has lifted a ban on the beatification of murdered Salvadoran Archbishop Oscar Romero.

For years, the Roman Catholic Church blocked the process because of concerns that he had Marxist ideas.

An outspoken critic of the military regime during El Salvador's bloody civil war, Archbishop Romero was shot dead while celebrating Mass in 1980.

Beatification, or declaring a person "blessed", is the necessary prelude to full sainthood.

The bishop was one of the main proponents of Liberation Theology - an interpretation of Christian faith through the perspective of the poor.

On Monday, the Pope said he was hoping for a swift beatification process.

"For me Romero is a man of God," the pontiff told journalists on the plane bringing him back from a trip to South Korea.

"There are no doctrinal problems and it is very important that [the beatification] is done quickly."

Archbishop Romero denounced the right-wing death squads that operated in the Central American nation at the time and the oppression against the poor, calling for an end to all political violence.

Left-wing rebels fought an insurgency against the US-backed right-wing government.

Some 75,000 people were killed in the civil war, which began in 1980 and ended in 1992 with a UN-brokered peace agreement.

Archbishop Romero was killed on 24 March 1980, aged 62, after ending his sermon in the capital, San Salvador.

No-one has ever been convicted in connection with his murder.

In 2010, then President Mauricio Funes - El Salvador's first left-wing leader since the end of the civil war - made an official apology.

"I am seeking pardon in the name of the state," Mr Funes said as he unveiled a mural honouring Oscar Romero at El Salvador's international airport.

The archbishop, he said, was a victim of right-wing death squads "who unfortunately acted with the protection, collaboration or participation of state agents".