Prime Minister Scott Morrison told the National Farmers' Federation Congress he wanted to have a "fair dinkum" conversation about the proposal, which has created tension within the coalition.

He defended Nationals leader Michael McCormack, whose leadership is now in the balance after internal criticism including the lack of action on an agriculture visa.

"We will work to establish an agriculture visa - that is the long-term solution, even the medium-term solution," Mr Morrison said in Canberra on Thursday.

"It has been Michael McCormack and I who have been working on this plan from the day we signed up as a coalition."

He said the deputy prime minister had championed the idea in a constructive and practical way.

Drawing on his time as immigration minister, Mr Morrison said new visa categories could not be introduced hastily.

For the upcoming harvest, the government is urging farmers to register their labour shortages on a new database to help match Australian workers with vacancies.

The NFF has lobbied for an agriculture visa, saying Australian farms are in dire need of more workers.

"We've never ever said we don't think that's a good idea but we have to go about it in the right way and it's not a silver bullet," Mr Morrison said.

"It doesn't solve all the problems for upcoming harvest."

NFF president Fiona Simson said she was delighted Mr Morrison confirmed he committed to a new work visa category.

"Mr Morrison today gave agriculture the confidence it was seeking, that an agricultural visa would become a reality," Ms Simson said.

"Right now farmers across the country, are struggling to find the pickers and packers needed to harvest and prepare their summer crop for market."

Vegetable industry peak body chief James Whiteside welcomed the commitment, but warned of significant long-term ramifications if an agriculture visa wasn't introduced.

"Our entire industry will not be able to reach its full potential due to a chronic shortage of labour," the Ausveg CEO said.

Australian Associated Press