Senate Democrats are urging President Trump to step up the administration’s support for coronavirus testing, saying they are “deeply troubled” by the administration’s recent plan.

“We fundamentally reject the notion that the federal government bears this little responsibility in increasing testing capacity,” Democrats wrote in the letter to Trump sent Tuesday.

“The Trump Administration must not shirk its responsibilities and leave states and Tribes to fend for themselves,” they added.

Testing has emerged as a key point of contention between the administration and Democrats, who have warned—along with public health experts—that testing capacity needs to be ramped up before states begin lifting social distancing restrictions.

The White House released a "blueprint" last month for its testing strategy, largely placing the onus on states to "develop testing plans and rapid response programs." The White House said that it should act as a "supplier of last resort."

Senate Minority Leader Charles Schumer (D-N.Y.) said earlier Tuesday that he thought the administration has been “derelict” on testing.

Democrats, in the letter to Trump, are urging him to invoke the Defense Production Act to help ramp up testing, as well as coordinate with states on lab capacity and contract tracing, the process of finding individuals that have been in contact with an infected person.

As part of the strategy required by the “interim” coronavirus bill passed last week, Democrats are requesting the development of a testing pipeline, that the administration help administer tests and implement an antibody testing program.

“Your Administration needs to do much more to stand up enough testing to effectively trace, control, and suppress the spread of the virus, and it is essential that you do so in a manner that is transparent and accountable,” they added.