Hillary Clinton’s rumored vice presidential pick Sen. Tim Kaine defended his vote for fast-tracking the Trans-Pacific Partnership (TPP) on Thursday.

Kaine, who spoke to The Intercept after an event at a Northern Virginia mosque, praised the agreement as an improvement of the status quo, but maintained that he had not yet decided how to vote on final approval of the agreement. By contrast, Hillary Clinton has qualified her previous encouragement of the agreement, and now says she opposes it.

Kaine’s measured praise of the agreement could signal one of two things. Either he is out of the running for the vice presidential spot, as his position on this major issue stands in opposition to hers. Or, by picking him, Clinton is signaling that her newly declared opposition to the agreement is not sincere. The latter explanation would confirm the theory offered by U.S. Chamber of Commerce head Tom Donohue, among others, who has said that Clinton is campaigning against the TPP for political reasons but would ultimately implement the deal.

With only hours to go before Clinton announced her pick, Kaine was unabashed in defending his vote. “Fast track was to give President Obama the same tools to negotiate a trade deal that every president since Gerald Ford has had, and of course I voted for that,” Kaine said. “Why would I not give to this president the same tools to negotiate a trade deal that other presidents have had?”

Fast track powers allow the president to submit the agreement to Congress for an up or down vote without any changes. Fast track was widely viewed as necessary for assuring final passage of the agreement, and few Democrats supported authorizing those powers for Obama for the TPP. Only 28 House Democrats and 13 Senate Democrats voted in favor of fast track.

Kaine explained that now that the final agreement has been reached in international negotiations, he is weighing whether or not to vote for it.

“I am having discussions with groups around Virginia about the treaty itself. I see much in it to like. I think it’s an upgrade of labor standards. I think it’s an upgrade of environmental standards, I think it’s an upgrade in intellectual property protections,” he explained. “I do see at least right now that there is one element that I do have some very significant concerns about. And that is the dispute resolution mechanism. And I’ve got a lot of concerns about that. So I have no idea about when a vote would be because the majority will make that decision. And I’m not in the majority. But long before there would be a vote on that I’m trying to climb the learning curve on the areas where I have questions. So again, much of it I see I think as a significant improvement over the status quo. The dispute resolution mechanism I still have some significant concerns about.”

The dispute resolution provisions Kaine is referring to would expand the corporate right to sue governments over alleged violations of the TPP. Many fear that it infringes on national sovereignty.

Kaine’s praise of the TPP’s expansion of intellectual property rights stands in opposition to concerns from many that the agreement will expand patent monopolies over life-saving drugs. The medical charity group Doctors Without Borders has warned that TPP provisions would make some pharmaceutical drugs too expensive for the world’s poor.