Rail electrification is already going ahead in south Wales but no decision has yet been made on the north.
The Wales Office and Welsh government are working with businesses to make the case for the investment needed for the project to get the go-ahead.
But Mr Osborne said a decision would be affected by the HS2 project and a rail hub possibly being created in Crewe.
Electrification means faster and more reliable services which help businesses and their workers who commute.
Welsh Secretary Stephen Crabb also said electrification could be a game-changer and could happen in the longer-term.
Speaking on a visit to Denbighshire, Mr Osborne said: "Lets make the decision first on HS2 because that new rail hub at Crewe will be crucial for north Wales and it's crucial for the investments we're making in the north Wales economy."

Anne sent the eight-line verse to a friend in 1942.
The auction house in the Netherlands had valued the rare, handwritten note at €30,000-€50,000.
Anne is best remembered for her diaries of life as a German-born Jew in occupied Amsterdam in World War Two.
The poem was signed and dated 28 March 1942, which was less than four months before the Frank family moved into a secret apartment to hide from German forces.
Addressed "Dear Cri-Cri", it was given to Christiane van Maarsen, the older sister of one of Anne's best friends, Jacqueline.
The Bubb Kuyper auction house, based in the Dutch city of Haarlem, said Jacqueline van Maarsen was selling the poem because she knew her sister, who died in 2006, did not see it as a prized possession.
In a note published on the auctioneers' website, she wrote, "My sister (nicknamed Cri-Cri) tore this page out of her poezie album and gave it to me around 1970. I know that my sister was not as attached to this verse from Anne to her as I am to the verse Anne addressed to me."
It was common for girls of the era to collate notes from friends in scrapbooks they called poezie albums.
The first four lines of the poem, which encouraged the older sister to work hard at school, are known to have been copied from a magazine.
The second four carried on the same edifying theme, but may be Anne's original work.
The auctioneers noted that Anne switched her style of handwriting midway through writing.
Her diaries have become one the most important documents to emerge from the Holocaust. Her father published them after she died of typhus in the Bergen-Belsen Nazi death camp aged 15.

He will star in the project, translated as Stalin's Sofa, which will be directed by actress Fanny Ardant, said The Hollywood Reporter.
The film is based on French author Jean-Daniel Baltassat's 2013 novel.
Depardieu was presented with a Russian passport by Vladimir Putin in 2013 after moving to avoid higher taxes in his native France.
Mr Depardieu's move to Russia came after he criticised French President Francois Hollande's plans to raise taxes to 75% for those earning more than 1m euros (Â£817,400).
The actor accused the government of punishing "success, creation and talent".
In 2011, he played the lead role in the film Rasputin, a Franco-Russian production about the life of eccentric monk.
He also recently announced a movie about WW2 French fighter aces who flew alongside Red Air Force pilots over the Eastern Front.
Josef Stalin, the supreme ruler of the Soviet Union for more than 25 years, helped the allies defeat Nazism.
But his regime of terror caused the death and suffering of tens of millions.
The new movie, to be produced by French/Portuguese company Leopardo Filmes, is to be set in the 1950s Soviet Union and will centre on a young artist commissioned to create Stalin's monument.
There is a "really strong case" for the electrification of the north Wales rail lines, Chancellor George Osborne said.
[NEXT_CONCEPT]
A poem by Dutch schoolgirl Anne Frank written shortly before her family went into hiding from the Nazis has sold at auction for €140,000 ($148,000; £120,000), well over the estimate.
[NEXT_CONCEPT]
French actor Gerard Depardieu is to play Russian dictator Josef Stalin in a new film, according to reports.