A Turkish court ruled on Friday that the American evangelical Christian pastor at the centre of a row between Ankara and Washington could go free, a move that could be the first step towards mending ties between the NATO allies.

The court sentenced Andrew Brunson to three years and 1-1/2 months in prison on terrorism charges, but said he would not serve any further jail time. The pastor, who has lived in Turkey for more than 20 years, was put in prison two years ago and has been under house arrest since July.

U.S. President Donald Trump, who has imposed sanctions on Turkey in an attempt to secure Brunson's freedom, tweeted: "PASTOR BRUNSON JUST RELEASED. WILL BE HOME SOON!"

Dressed in a black suit, white shirt and red tie, the North Carolina native wept as the decision was announced, witnesses said. Before the judge's ruling he had told the court: "I am an innocent man. I love Jesus, I love Turkey."

After the ruling, Brunson's lawyer told reporters the pastor was likely to leave Turkey. The U.S. military has a plan to fly Brunson back to America on a military aircraft, officials told Reuters.

The diplomatic stand-off over Brunson, who had been pastor of the Izmir Resurrection Church, had accelerated a sell-off in Turkey's lira currency, worsening a financial crisis.

Brunson had been accused of links to Kurdish militants and supporters of Fethullah Gulen, the cleric blamed by Turkey for a coup attempt in 2016. Brunson denied the accusation and Washington had demanded his immediate release.

Witnesses told the court in the western town of Aliaga that testimonies against the pastor attributed to them were inaccurate.

Brunson's wife Norine looked on from the visitors' area.

Brunson's mother told Reuters she and his father were elated at the news. "We are overjoyed that God has answered the prayers of so many people around the world," she said.

Trump has scored points with evangelical Christians, a large part of his political base, by focusing on the Brunson case. The release could boost Trump's ability to encourage such voters to support Republicans in large numbers in Nov. 6 elections, which will determine whether the party keeps control of Congress.

The heavily conservative constituency voted overwhelmingly for Trump in 2016. He has called Brunson a "great Christian", and Vice President Mike Pence, the White House's top emissary to evangelicals, had urged Americans to pray for Brunson.

U.S. broadcaster NBC said on Thursday that Washington had done a secret deal with Ankara to secure Brunson's release.

The lira stood at 5.910 to the dollar at 1336 GMT, little changed on the day after firming 3 percent on Thursday on expectations that Brunson would be freed.

Relations between the two NATO allies are also under strain over U.S. support for Kurdish fighters in northern Syria, Turkey's plans to buy a Russian missile defence system, and the U.S. jailing of a executive at a Turkish state bank in an Iran sanctions-busting case.

With Brunson's release, attention may now turn to the fate of a Turkish-U.S. national and former NASA scientist in jail in Turkey on terrorism charges, as well as three local employees of the U.S. consulate who have also been detained.

Washington wants all these people released, while Ankara has demanded the extradition of Gulen. The cleric, who was lived in self-imposed exile in the United States since 1999, denies any role in the attempted coup.

Friday's decision could be a first step to ease tensions.

Further moves which have been discussed include the return to Turkey of bank executive Hakan Attila to serve out his sentence, the release of the U.S. consular staff, and agreement that the U.S. Treasury avoid draconian steps against Halkbank , the state lender.