A project manager is negotiating a contract modification with a critical vendor who is requesting additional compensation due to scope changes. The vendor has valid justifications, but the requested amount exceeds the project manager's approval authority. Which TWO actions should the project manager take FIRST?

Analyze the vendor's cost justification and validate the scope changes that triggered the request

Immediately escalate to the sponsor since the amount exceeds approval authority

Explore alternative solutions that might address the vendor's concerns within existing budget constraints

Accept the vendor's request since they are critical to project success

Reject the request to maintain project budget constraints

Document the negotiation for future reference and lessons learned